bundle.js

(function(){function r(e,n,t){function o(i,f){if(!n[i]){if(!e[i]){var c="function"==typeof require&&require;if(!f&&c)return c(i,!0);if(u)return u(i,!0);var a=new Error("Cannot find module '"+i+"'");throw a.code="MODULE_NOT_FOUND",a}var p=n[i]={exports:{}};e[i][0].call(p.exports,function(r){var n=e[i][1][r];return o(n||r)},p,p.exports,r,e,n,t)}return n[i].exports}for(var u="function"==typeof require&&require,i=0;i<t.length;i++)o(t[i]);return o}return r})()({1:[function(require,module,exports){
  const P2PT = require('p2pt')
  
  // Canvas Draw --------------------------------------
  
  const canvas = document.querySelector('#canvas');
  const canvas_container = document.getElementsByClassName('board-container')[0];
  document.getElementById('menu_pen').addEventListener('click',()=>{setMode(1)});
  document.getElementById('menu_eraser').addEventListener('click',()=>{setMode(2)});
  document.getElementById('menu_pointer').addEventListener('click',()=>{setMode(3)});
  document.getElementById('menu_undo').addEventListener('click',()=>{Undo()});
  document.getElementById('menu_redo').addEventListener('click',()=>{Redo()});
  document.getElementById('btn-export').addEventListener('click',()=>{DownloadCanvas();});
  document.getElementById('btn-clear').addEventListener('click',()=>{ClearCanvas();});
  document.getElementById('btn-set-name').addEventListener('click',()=>{SetNickname();});
  document.getElementById('btn-open').addEventListener('click',()=>{OpenLocalFile();});
  document.getElementById('btn-download').addEventListener('click',()=>{saveFile();});
  
  colors.forEach(element => { element.addEventListener('click',(e)=>{setBrushColor(element.title)})});
  
  
  document.getElementById('btn-join-room').addEventListener('click',()=>{
      room_code = document.getElementsByName("join-room-code")[0].value;
      document.getElementsByName("join-room-code")[1].value = room_code;
      document.getElementById("share-modal-back").style.display="none";
      document.getElementById('btn-join-room').style.display="none";
      document.getElementsByName("join-room-code")[0].setAttribute('readonly',"true")
      ShareModal(1)
      document.getElementById('btn-create-room').classList.add("disabled");
      JoinRoom(room_code)
    });
    
    document.getElementById('btn-create-room').addEventListener('click',()=>{
      document.getElementsByName("join-room-code")[1].value = RandomCoder();
      document.getElementById("share-modal-back").style.display="none";
      ShareModal(2)
      document.getElementById('btn-create-room').style.display="none";
      document.getElementById('btn-share-room').style.display="block";
      room_code = document.getElementsByName("join-room-code")[1].value;
      document.getElementsByName("join-room-code")[0].value = room_code;
      document.getElementById("btn-join-room").classList.add("disabled");
      JoinRoom(room_code)
    });
  
  
  var fileHandle= false;
  var p2pt = false;
  var HomeRoom=""
  var undo_array = []
  var redo_array =[]
  var me = {
      name:"One For All",
      id:"",
      pos: { x: 0, y: 0 },
      brush_down: false,
      mode:"pen",
      profile_color:"orangered",
      pre_pos: { x: 0, y: 0 },
      brush_size: 5,
      brush_color: "#1d809f",
      undo_array:[],
      redo_array:[],
      stroke_array:[],
      ctx:canvas.getContext('2d'),
      is_peer:false,
      peer:false
  }
  
  let peer_template = {
      name:"All For One",
      id:"",
      pos: { x: 0, y: 0 },
      brush_down: false,
      mode:"pen",
      profile_color:"pink",
      pre_pos: { x: 0, y: 0 },
      brush_size: 5,
      brush_color: "#1d809f",
      undo_array:[],
      redo_array:[],
      stroke_array:[],
      ctx:canvas.getContext('2d'),
      is_peer:true,
      peer:false
  }
  
  var Peers={};
  
  window.addEventListener('load', () => {
      canvas.addEventListener('mousedown', startPainting);
      canvas.addEventListener('mouseup', stopPainting);
      canvas.addEventListener('mousemove', selfDraw);
      canvas.addEventListener('touchstart', (e)=>{
          let x;
          if(e.touches.length==1){
              var touch_single=true;
              if(touch_single){
                  startMobilePainting(e)
                  clearTimeout(x);
              }else{
                  x = setTimeout(()=>{touch_single=false},200)
              }
          }
      });
      canvas.addEventListener('touchend', startMobilePainting)
      canvas.addEventListener("touchmove", function (e) {
          
          //if (!me.brush_down) { startMobilePainting(e) }
          if(e.touches.length==1){
              var touch_single=true;
              if(touch_single){
                  var touch = e.touches[0];
                  var mouseEvent = new MouseEvent("mousemove", {
                      clientX: touch.clientX,
                      clientY: touch.clientY
                  });
                  selfDraw(mouseEvent)
              }
              
          }
          //alert(JSON.stringify(e.touches))
          //
      }, false);
  });
  
  
  me.profile_color = RandomColor()
  function getPosition(event) {
      var x = event.clientX - canvas_container.offsetLeft + canvas_container.scrollLeft;
      var y = event.clientY - canvas_container.offsetTop + canvas_container.scrollTop;
      return [x, y]
  }
  function startPainting(event) {
      me.brush_down = true;
      PushToUndo();
      ClearRedo();
      BroadCast("draw-start",me.id,[me.pre_pos.x, me.pre_pos.y]);
      [me.pre_pos.x, me.pre_pos.y] = getPosition(event);
      selfDraw(event);
  }
  function startMobilePainting(event) {
      me.brush_down = true;
      PushToUndo();
      ClearRedo();
      [me.pre_pos.x, me.pre_pos.y] = getPosition(event.touches);
      BroadCast("draw-start",me.id,[me.pre_pos.x, me.pre_pos.y]);
  }
  function pre_pos(who) {
      who.pre_pos.x = who.pos.x;
      who.pre_pos.y = who.pos.y;
  }
  
  function stroke_array(who,pos){
      who.stroke_array.push(pos);
  }
  
  function stopPainting() { me.brush_down = false; BroadCast("draw-stop",me.id,"");}
  
  function selfDraw(event){
      if (!me.brush_down) return;
      var pos = getPosition(event)
      stroke_array(me,pos)
      BroadCast('draw-pos',me.id,pos)
      sketch(me)
      //console.log("!",me.stroke_array);
      
  }
  
  function PointerMode(state){
      if(state){
          canvas.style.cursor = 'auto'
      }else{
          canvas.style.cursor = 'crosshair';
      }
  }
  
  function setMode(mode){
      modeIcons=['<i class="fa fa-bars"></i>','<i class="fa fa-pen"></i>','<i class="fa fa-eraser"></i>','<i class="fa fa-mouse-pointer"></i>'];
      modes = ["view","pen","eraser","mouse"];
      if(mode<4){
          me.mode=modes[mode];
          document.getElementsByClassName('btn-main')[0].innerHTML = modeIcons[mode];
      }
      if(modes[mode]=="mouse"){
          PointerMode(true)
      }else{
          PointerMode(false)
      }
      BroadCast('ptr-mode',me.id,[me.mode,me.brush_color])
  }
  
  function SetNickname(){
      var name = document.getElementsByName('nick-name')[0].value;
      if(name.trim() === ''){
          me.name = "Peer";
          return;
      }else{
          me.name = name;
          
          BroadCast("set-name",me.id,me.name)
      }
  }
  
  function setBrushColor(color){
      me.brush_color = color;
      document.getElementById('dropdownMenuButton').style.background = color;
      setMode(1)
      BroadCast('ptr-mode',me.id,[me.mode,me.brush_color])
  }
  
  // Downloading as Image
  var DownloadCanvas = function(){
      var link = document.createElement('a');
      link.download = 'drawboard.png';
      link.href = canvas.toDataURL()
      link.click();
    }
  

    // Saving Locally to File
    $(window).bind('keydown', function(event) {
      if (event.ctrlKey || event.metaKey) {
          switch (String.fromCharCode(event.which).toLowerCase()) {
          case 's':
              event.preventDefault();
              // alert('ctrl-s');
              saveFile();
            }
        }
    });

  
  async function saveFile() {
    const options = {
      types: [
        {
          description: 'Draw Board Files',
          accept: {
            'image/board': ['.board'],
          },
        },
      ],
    };
    if(!fileHandle){
      const handle = await window.showSaveFilePicker(options);
      writeFile(handle,canvas.toDataURL("image/png"))
    }else{
      writeFile(fileHandle,canvas.toDataURL("image/png"))
    }
    // return handle;
  }

  async function LoadBoard(){
    const options = {
      types: [
        {
          description: 'Draw Board Files',
          accept: {
            'image/board': ['.board'],
          },
        },
      ],
    };
   
    [handle] = await window.showOpenFilePicker(options);
      var fileData = await handle.getFile();
      if(confirm("Load Board from File?")){
        CanvasFromURL(fileData.name)
      }
  }

  function OpenLocalFile(){
    var file = document.getElementById('btn-input-file')
    file.click();
    file.addEventListener('change', readSingleFile)
  }

  async function readSingleFile(e) {
    var file = e.target.files[0];
    if (!file) {
      return;
    }
    var reader = new FileReader();
    reader.onload = function(e) {
      var contents = e.target.result;
      CanvasFromURL(contents)
    };
    reader.readAsText(file);
  }

  async function CanvasFromURL(data){
    console.log(data)
    var ctx = me.ctx;
    var img = new Image;
    img.onload = function(){
      ctx.drawImage(img,0,0);
    };
    img.src = data;
  }
  
  async function writeFile(fHandle, contents) {
      fileHandle=fHandle
      const writable = await fHandle.createWritable();
      await writable.write(contents);
      await writable.close();
  }
  
  function sketch(who) {
      
      if (!who.brush_down) return;
      who.ctx.beginPath();
      who.ctx.lineCap = 'round';
      who.ctx.strokeStyle = who.brush_color;
      who.ctx.lineWidth = who.brush_size;
      if(who.mode=="pen"){
          // if(who.is_peer){
          //     [who.pre_pos.x, who.pre_pos.y] = who.stroke_array[0];
          // }
          who.ctx.globalCompositeOperation="source-over";
          while(who.stroke_array.length>0){
              console.log(who.stroke_array);
              [who.pos.x,who.pos.y] = who.stroke_array.shift()
              who.ctx.moveTo(who.pre_pos.x, who.pre_pos.y);
              pre_pos(who)  
              //console.log(who.pos);
              who.ctx.lineTo(who.pos.x, who.pos.y);
              who.ctx.stroke();
          }
      
      }else if(who.mode=="eraser"){
          who.ctx.globalCompositeOperation="destination-out";
          while(who.stroke_array.length>0){
              who.ctx.strokeStyle = false;
              who.ctx.lineWidth = 20;
              [who.pos.x,who.pos.y] = who.stroke_array.shift()
              who.ctx.moveTo(who.pre_pos.x,who.pre_pos.y);
              pre_pos(who)
              //console.log("Erasing");
          }
          who.ctx.lineTo(who.pos.x, who.pos.y);
          who.ctx.stroke(); 
      }
      who.stroke_array=[]
  }
  
  
  // Both Peer and Me Functions
  function PushToUndo(){
      if(undo_array.length>=5){
         undo_array.shift()
      }
      undo_array.push(canvas.toDataURL());
  }
  
  function PushToRedo(what){
      if(redo_array.length>=5){
         redo_array.shift()
      }
      redo_array.push(what)
  }
  
  function ClearRedo(){
      redo_array=[]
  }
  
  function KeyPress(e) {
    var evtobj = window.event? event : e
    if (evtobj.keyCode == 90 && evtobj.ctrlKey) {
      Undo();
      console.log("Shortcut Undo");
    }else if (evtobj.keyCode == 89 && evtobj.ctrlKey) {
      Redo();
      console.log("Shortcut Undo");
    }
}

document.onkeydown = KeyPress;

  function Undo(){
      PushToRedo(canvas.toDataURL());
      if(undo_array.length<=0){return}
      var img = new Image;
      ClearCanvas()
      img.src = undo_array.pop()
      img.onload = function(){
          me.ctx.drawImage(img,0,0); // Or at whatever offset you like
      };
      //PushToRedo(img.src);
  }

  function Redo(){
      PushToUndo(canvas.toDataURL())
      if(redo_array.length<=0){return}
      var img = new Image;
      ClearCanvas()
      img.src = redo_array.pop()
      img.onload = function(){
          me.ctx.drawImage(img,0,0); // Or at whatever offset you like
      };
      //PushToUndo(img.src)
  }
  
  function ClearCanvas(){
      me.ctx.clearRect(0, 0, canvas.width, canvas.height);
      BroadCast("draw-clear",me.id,"");
  }
  
  
  //--------Peer Connectivity
  
  function JoinRoom(room){
    var img = new Image()
    code = encodeURIComponent("https://elvistony.github.io/board-io/#"+room);
    img.src = "https://api.qrserver.com/v1/create-qr-code/?size=120x120&data="+code;
    img.classList.add("img")
    img.classList.add("m-3")
    img.classList.add("rounded")
    img.onload = function (){
      document.getElementById('qrcode').appendChild(img)
    }
      console.log('Joining Room:',room)
      init (room) 
  }
  
  function BroadCast(mode,who_id,what){
      console.log(mode,what);
      Object.keys(Peers).forEach(peer => {
          p2pt.send(Peers[peer].peer,JSON.stringify({
              type:mode,
              data:what
          }));
      });
  }
  
  function SetPeerNickname(who,what){
      Peers[who].name=what;
      document.getElementById(who).innerText = what;
      
  }
  
  function CreatePeer(who_id){
      who = Peers[who_id];
      document.getElementById("peer-array").innerHTML+=
      '<button class="set-name" id="'+who_id+'" style="background:'+who.profile_color+'">'+who.name+'</button>';
  }
  
  function RemovePeer(who_id){
      delete Peers[who_id];
      document.getElementById(who_id).outerHTML = "";
  }
  
  function IntroducePeer(){
      BroadCast("hi-there",me.id,[me.name,me.profile_color])
  }
  
  function init (room) {
      let announceURLs = [
      "wss://tracker.sloppyta.co:443/announce",
      "wss://tracker.novage.com.ua:443/announce",
      "wss://tracker.openwebtorrent.com",
      "wss://tracker.webtorrent.io",
      "wss://tracker.btorrent.xyz",
      // "wss://tracker.novage.com.ua",
      "wss://tracker.files.fm:7073/announce",
      // "wss://tracker.openwebtorrent.com",
      // "wss://tracker.btorrent.xyz",
      // "wss://tracker.fastcast.nz"
      ]
      p2pt = new P2PT(announceURLs, 'boardio'+room)
      listen ();
      
  }
  
  
  function listen () {
      p2pt.on('peerconnect', (peer) => {
          Peers[peer.id] = Object.assign({},peer_template);
          Peers[peer.id].peer = peer;
          console.log(Peers);
          document.getElementsByClassName('btn-main')[0].classList.add("btn-connected")
          IntroducePeer()
          document.getElementById('peers').innerHTML=Object.keys(Peers).length;
          //sending Intro msg
      })
      p2pt.on('peerclose', (peer) => {
          console.log(peer.id+" disconnected");
          RemovePeer(peer.id);
          if(Object.keys(Peers).length==0){
              document.getElementsByClassName('btn-main')[0].classList.remove("btn-connected")
          }
      })
  
      p2pt.on('msg', (peer, msg) => {
          msg = JSON.parse(msg)
          //console.log(msg);
          if(msg.type=='ptr-mode'){
              Peers[peer.id].mode = msg.data[0];
              Peers[peer.id].brush_color = msg.data[1];
          }else if(msg.type=="draw-start"){
              Peers[peer.id].brush_down = true;
              Peers[peer.id].pre_pos=msg.data;
              console.log(peer.id,"Started Drawing",Peers[peer.id].brush_down)
          }else if(msg.type=="draw-stop"){
              console.log(peer.id,"Stopped Drawing")
              console.log(Peers[peer.id]);
              Peers[peer.id].brush_down = false;    
          }else if(msg.type=="draw-pos"){
              Peers[peer.id].stroke_array.push(msg.data)
              console.log(Peers[peer.id].stroke_array)
              sketch(Peers[peer.id])
          }else if(msg.type=="draw-clear"){
              ClearCanvas()
          }else if(msg.type=="set-name"){
              SetPeerNickname(peer.id,msg.data);
          }else if(msg.type=="hi-there"){
              Peers[peer.id].name = msg.data[0];
              Peers[peer.id].profile_color = msg.data[1];
              CreatePeer(peer.id);
              
          }else{
              console.log(msg);
          }
      })
      p2pt.start()
    
    // End of Application Code
  }
  },{"p2pt":16}],2:[function(require,module,exports){
  'use strict'
  
  exports.byteLength = byteLength
  exports.toByteArray = toByteArray
  exports.fromByteArray = fromByteArray
  
  var lookup = []
  var revLookup = []
  var Arr = typeof Uint8Array !== 'undefined' ? Uint8Array : Array
  
  var code = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
  for (var i = 0, len = code.length; i < len; ++i) {
    lookup[i] = code[i]
    revLookup[code.charCodeAt(i)] = i
  }
  
  // Support decoding URL-safe base64 strings, as Node.js does.
  // See: https://en.wikipedia.org/wiki/Base64#URL_applications
  revLookup['-'.charCodeAt(0)] = 62
  revLookup['_'.charCodeAt(0)] = 63
  
  function getLens (b64) {
    var len = b64.length
  
    if (len % 4 > 0) {
      throw new Error('Invalid string. Length must be a multiple of 4')
    }
  
    // Trim off extra bytes after placeholder bytes are found
    // See: https://github.com/beatgammit/base64-js/issues/42
    var validLen = b64.indexOf('=')
    if (validLen === -1) validLen = len
  
    var placeHoldersLen = validLen === len
      ? 0
      : 4 - (validLen % 4)
  
    return [validLen, placeHoldersLen]
  }
  
  // base64 is 4/3 + up to two characters of the original data
  function byteLength (b64) {
    var lens = getLens(b64)
    var validLen = lens[0]
    var placeHoldersLen = lens[1]
    return ((validLen + placeHoldersLen) * 3 / 4) - placeHoldersLen
  }
  
  function _byteLength (b64, validLen, placeHoldersLen) {
    return ((validLen + placeHoldersLen) * 3 / 4) - placeHoldersLen
  }
  
  function toByteArray (b64) {
    var tmp
    var lens = getLens(b64)
    var validLen = lens[0]
    var placeHoldersLen = lens[1]
  
    var arr = new Arr(_byteLength(b64, validLen, placeHoldersLen))
  
    var curByte = 0
  
    // if there are placeholders, only get up to the last complete 4 chars
    var len = placeHoldersLen > 0
      ? validLen - 4
      : validLen
  
    var i
    for (i = 0; i < len; i += 4) {
      tmp =
        (revLookup[b64.charCodeAt(i)] << 18) |
        (revLookup[b64.charCodeAt(i + 1)] << 12) |
        (revLookup[b64.charCodeAt(i + 2)] << 6) |
        revLookup[b64.charCodeAt(i + 3)]
      arr[curByte++] = (tmp >> 16) & 0xFF
      arr[curByte++] = (tmp >> 8) & 0xFF
      arr[curByte++] = tmp & 0xFF
    }
  
    if (placeHoldersLen === 2) {
      tmp =
        (revLookup[b64.charCodeAt(i)] << 2) |
        (revLookup[b64.charCodeAt(i + 1)] >> 4)
      arr[curByte++] = tmp & 0xFF
    }
  
    if (placeHoldersLen === 1) {
      tmp =
        (revLookup[b64.charCodeAt(i)] << 10) |
        (revLookup[b64.charCodeAt(i + 1)] << 4) |
        (revLookup[b64.charCodeAt(i + 2)] >> 2)
      arr[curByte++] = (tmp >> 8) & 0xFF
      arr[curByte++] = tmp & 0xFF
    }
  
    return arr
  }
  
  function tripletToBase64 (num) {
    return lookup[num >> 18 & 0x3F] +
      lookup[num >> 12 & 0x3F] +
      lookup[num >> 6 & 0x3F] +
      lookup[num & 0x3F]
  }
  
  function encodeChunk (uint8, start, end) {
    var tmp
    var output = []
    for (var i = start; i < end; i += 3) {
      tmp =
        ((uint8[i] << 16) & 0xFF0000) +
        ((uint8[i + 1] << 8) & 0xFF00) +
        (uint8[i + 2] & 0xFF)
      output.push(tripletToBase64(tmp))
    }
    return output.join('')
  }
  
  function fromByteArray (uint8) {
    var tmp
    var len = uint8.length
    var extraBytes = len % 3 // if we have 1 byte left, pad 2 bytes
    var parts = []
    var maxChunkLength = 16383 // must be multiple of 3
  
    // go through the array every three bytes, we'll deal with trailing stuff later
    for (var i = 0, len2 = len - extraBytes; i < len2; i += maxChunkLength) {
      parts.push(encodeChunk(uint8, i, (i + maxChunkLength) > len2 ? len2 : (i + maxChunkLength)))
    }
  
    // pad the end with zeros, but make sure to not forget the extra bytes
    if (extraBytes === 1) {
      tmp = uint8[len - 1]
      parts.push(
        lookup[tmp >> 2] +
        lookup[(tmp << 4) & 0x3F] +
        '=='
      )
    } else if (extraBytes === 2) {
      tmp = (uint8[len - 2] << 8) + uint8[len - 1]
      parts.push(
        lookup[tmp >> 10] +
        lookup[(tmp >> 4) & 0x3F] +
        lookup[(tmp << 2) & 0x3F] +
        '='
      )
    }
  
    return parts.join('')
  }
  
  },{}],3:[function(require,module,exports){
  const EventEmitter = require('events')
  
  class Tracker extends EventEmitter {
    constructor (client, announceUrl) {
      super()
  
      this.client = client
      this.announceUrl = announceUrl
  
      this.interval = null
      this.destroyed = false
    }
  
    setInterval (intervalMs) {
      if (intervalMs == null) intervalMs = this.DEFAULT_ANNOUNCE_INTERVAL
  
      clearInterval(this.interval)
  
      if (intervalMs) {
        this.interval = setInterval(() => {
          this.announce(this.client._defaultAnnounceOpts())
        }, intervalMs)
        if (this.interval.unref) this.interval.unref()
      }
    }
  }
  
  module.exports = Tracker
  
  },{"events":8}],4:[function(require,module,exports){
  const debug = require('debug')('bittorrent-tracker:websocket-tracker')
  const Peer = require('simple-peer')
  const randombytes = require('randombytes')
  const Socket = require('simple-websocket')
  
  const common = require('../common')
  const Tracker = require('./tracker')
  
  // Use a socket pool, so tracker clients share WebSocket objects for the same server.
  // In practice, WebSockets are pretty slow to establish, so this gives a nice performance
  // boost, and saves browser resources.
  const socketPool = {}
  
  const RECONNECT_MINIMUM = 10 * 1000
  const RECONNECT_MAXIMUM = 60 * 60 * 1000
  const RECONNECT_VARIANCE = 5 * 60 * 1000
  const OFFER_TIMEOUT = 50 * 1000
  
  class WebSocketTracker extends Tracker {
    constructor (client, announceUrl, opts) {
      super(client, announceUrl)
      debug('new websocket tracker %s', announceUrl)
  
      this.peers = {} // peers (offer id -> peer)
      this.socket = null
  
      this.reconnecting = false
      this.retries = 0
      this.reconnectTimer = null
  
      // Simple boolean flag to track whether the socket has received data from
      // the websocket server since the last time socket.send() was called.
      this.expectingResponse = false
  
      this._openSocket()
    }
  
    announce (opts) {
      if (this.destroyed || this.reconnecting) return
      if (!this.socket.connected) {
        this.socket.once('connect', () => {
          this.announce(opts)
        })
        return
      }
  
      const params = Object.assign({}, opts, {
        action: 'announce',
        info_hash: this.client._infoHashBinary,
        peer_id: this.client._peerIdBinary
      })
      if (this._trackerId) params.trackerid = this._trackerId
  
      if (opts.event === 'stopped' || opts.event === 'completed') {
        // Don't include offers with 'stopped' or 'completed' event
        this._send(params)
      } else {
        // Limit the number of offers that are generated, since it can be slow
        const numwant = Math.min(opts.numwant, 10)
  
        this._generateOffers(numwant, offers => {
          params.numwant = numwant
          params.offers = offers
          this._send(params)
        })
      }
    }
  
    scrape (opts) {
      if (this.destroyed || this.reconnecting) return
      if (!this.socket.connected) {
        this.socket.once('connect', () => {
          this.scrape(opts)
        })
        return
      }
  
      const infoHashes = (Array.isArray(opts.infoHash) && opts.infoHash.length > 0)
        ? opts.infoHash.map(infoHash => {
          return infoHash.toString('binary')
        })
        : (opts.infoHash && opts.infoHash.toString('binary')) || this.client._infoHashBinary
      const params = {
        action: 'scrape',
        info_hash: infoHashes
      }
  
      this._send(params)
    }
  
    destroy (cb = noop) {
      if (this.destroyed) return cb(null)
  
      this.destroyed = true
  
      clearInterval(this.interval)
      clearTimeout(this.reconnectTimer)
  
      // Destroy peers
      for (const peerId in this.peers) {
        const peer = this.peers[peerId]
        clearTimeout(peer.trackerTimeout)
        peer.destroy()
      }
      this.peers = null
  
      if (this.socket) {
        this.socket.removeListener('connect', this._onSocketConnectBound)
        this.socket.removeListener('data', this._onSocketDataBound)
        this.socket.removeListener('close', this._onSocketCloseBound)
        this.socket.removeListener('error', this._onSocketErrorBound)
        this.socket = null
      }
  
      this._onSocketConnectBound = null
      this._onSocketErrorBound = null
      this._onSocketDataBound = null
      this._onSocketCloseBound = null
  
      if (socketPool[this.announceUrl]) {
        socketPool[this.announceUrl].consumers -= 1
      }
  
      // Other instances are using the socket, so there's nothing left to do here
      if (socketPool[this.announceUrl].consumers > 0) return cb()
  
      let socket = socketPool[this.announceUrl]
      delete socketPool[this.announceUrl]
      socket.on('error', noop) // ignore all future errors
      socket.once('close', cb)
  
      // If there is no data response expected, destroy immediately.
      if (!this.expectingResponse) return destroyCleanup()
  
      // Otherwise, wait a short time for potential responses to come in from the
      // server, then force close the socket.
      var timeout = setTimeout(destroyCleanup, common.DESTROY_TIMEOUT)
  
      // But, if a response comes from the server before the timeout fires, do cleanup
      // right away.
      socket.once('data', destroyCleanup)
  
      function destroyCleanup () {
        if (timeout) {
          clearTimeout(timeout)
          timeout = null
        }
        socket.removeListener('data', destroyCleanup)
        socket.destroy()
        socket = null
      }
    }
  
    _openSocket () {
      this.destroyed = false
  
      if (!this.peers) this.peers = {}
  
      this._onSocketConnectBound = () => {
        this._onSocketConnect()
      }
      this._onSocketErrorBound = err => {
        this._onSocketError(err)
      }
      this._onSocketDataBound = data => {
        this._onSocketData(data)
      }
      this._onSocketCloseBound = () => {
        this._onSocketClose()
      }
  
      this.socket = socketPool[this.announceUrl]
      if (this.socket) {
        socketPool[this.announceUrl].consumers += 1
        if (this.socket.connected) {
          this._onSocketConnectBound()
        }
      } else {
        this.socket = socketPool[this.announceUrl] = new Socket(this.announceUrl)
        this.socket.consumers = 1
        this.socket.once('connect', this._onSocketConnectBound)
      }
  
      this.socket.on('data', this._onSocketDataBound)
      this.socket.once('close', this._onSocketCloseBound)
      this.socket.once('error', this._onSocketErrorBound)
    }
  
    _onSocketConnect () {
      if (this.destroyed) return
  
      if (this.reconnecting) {
        this.reconnecting = false
        this.retries = 0
        this.announce(this.client._defaultAnnounceOpts())
      }
    }
  
    _onSocketData (data) {
      if (this.destroyed) return
  
      this.expectingResponse = false
  
      try {
        data = JSON.parse(data)
      } catch (err) {
        this.client.emit('warning', new Error('Invalid tracker response'))
        return
      }
  
      if (data.action === 'announce') {
        this._onAnnounceResponse(data)
      } else if (data.action === 'scrape') {
        this._onScrapeResponse(data)
      } else {
        this._onSocketError(new Error(`invalid action in WS response: ${data.action}`))
      }
    }
  
    _onAnnounceResponse (data) {
      if (data.info_hash !== this.client._infoHashBinary) {
        debug(
          'ignoring websocket data from %s for %s (looking for %s: reused socket)',
          this.announceUrl, common.binaryToHex(data.info_hash), this.client.infoHash
        )
        return
      }
  
      if (data.peer_id && data.peer_id === this.client._peerIdBinary) {
        // ignore offers/answers from this client
        return
      }
  
      debug(
        'received %s from %s for %s',
        JSON.stringify(data), this.announceUrl, this.client.infoHash
      )
  
      const failure = data['failure reason']
      if (failure) return this.client.emit('warning', new Error(failure))
  
      const warning = data['warning message']
      if (warning) this.client.emit('warning', new Error(warning))
  
      const interval = data.interval || data['min interval']
      if (interval) this.setInterval(interval * 1000)
  
      const trackerId = data['tracker id']
      if (trackerId) {
        // If absent, do not discard previous trackerId value
        this._trackerId = trackerId
      }
  
      if (data.complete != null) {
        const response = Object.assign({}, data, {
          announce: this.announceUrl,
          infoHash: common.binaryToHex(data.info_hash)
        })
        this.client.emit('update', response)
      }
  
      let peer
      if (data.offer && data.peer_id) {
        debug('creating peer (from remote offer)')
        peer = this._createPeer()
        peer.id = common.binaryToHex(data.peer_id)
        peer.once('signal', answer => {
          const params = {
            action: 'announce',
            info_hash: this.client._infoHashBinary,
            peer_id: this.client._peerIdBinary,
            to_peer_id: data.peer_id,
            answer,
            offer_id: data.offer_id
          }
          if (this._trackerId) params.trackerid = this._trackerId
          this._send(params)
        })
        peer.signal(data.offer)
        this.client.emit('peer', peer)
      }
  
      if (data.answer && data.peer_id) {
        const offerId = common.binaryToHex(data.offer_id)
        peer = this.peers[offerId]
        if (peer) {
          peer.id = common.binaryToHex(data.peer_id)
          peer.signal(data.answer)
          this.client.emit('peer', peer)
  
          clearTimeout(peer.trackerTimeout)
          peer.trackerTimeout = null
          delete this.peers[offerId]
        } else {
          debug(`got unexpected answer: ${JSON.stringify(data.answer)}`)
        }
      }
    }
  
    _onScrapeResponse (data) {
      data = data.files || {}
  
      const keys = Object.keys(data)
      if (keys.length === 0) {
        this.client.emit('warning', new Error('invalid scrape response'))
        return
      }
  
      keys.forEach(infoHash => {
        // TODO: optionally handle data.flags.min_request_interval
        // (separate from announce interval)
        const response = Object.assign(data[infoHash], {
          announce: this.announceUrl,
          infoHash: common.binaryToHex(infoHash)
        })
        this.client.emit('scrape', response)
      })
    }
  
    _onSocketClose () {
      if (this.destroyed) return
      this.destroy()
      this._startReconnectTimer()
    }
  
    _onSocketError (err) {
      if (this.destroyed) return
      this.destroy()
      // errors will often happen if a tracker is offline, so don't treat it as fatal
      this.client.emit('warning', err)
      this._startReconnectTimer()
    }
  
    _startReconnectTimer () {
      const ms = Math.floor(Math.random() * RECONNECT_VARIANCE) + Math.min(Math.pow(2, this.retries) * RECONNECT_MINIMUM, RECONNECT_MAXIMUM)
  
      this.reconnecting = true
      clearTimeout(this.reconnectTimer)
      this.reconnectTimer = setTimeout(() => {
        this.retries++
        this._openSocket()
      }, ms)
      if (this.reconnectTimer.unref) this.reconnectTimer.unref()
  
      debug('reconnecting socket in %s ms', ms)
    }
  
    _send (params) {
      if (this.destroyed) return
      this.expectingResponse = true
      const message = JSON.stringify(params)
      debug('send %s', message)
      this.socket.send(message)
    }
  
    _generateOffers (numwant, cb) {
      const self = this
      const offers = []
      debug('generating %s offers', numwant)
  
      for (let i = 0; i < numwant; ++i) {
        generateOffer()
      }
      checkDone()
  
      function generateOffer () {
        const offerId = randombytes(20).toString('hex')
        debug('creating peer (from _generateOffers)')
        const peer = self.peers[offerId] = self._createPeer({ initiator: true })
        peer.once('signal', offer => {
          offers.push({
            offer,
            offer_id: common.hexToBinary(offerId)
          })
          checkDone()
        })
        peer.trackerTimeout = setTimeout(() => {
          debug('tracker timeout: destroying peer')
          peer.trackerTimeout = null
          delete self.peers[offerId]
          peer.destroy()
        }, OFFER_TIMEOUT)
        if (peer.trackerTimeout.unref) peer.trackerTimeout.unref()
      }
  
      function checkDone () {
        if (offers.length === numwant) {
          debug('generated %s offers', numwant)
          cb(offers)
        }
      }
    }
  
    _createPeer (opts) {
      const self = this
  
      opts = Object.assign({
        trickle: false,
        config: self.client._rtcConfig,
        wrtc: self.client._wrtc
      }, opts)
  
      const peer = new Peer(opts)
  
      peer.once('error', onError)
      peer.once('connect', onConnect)
  
      return peer
  
      // Handle peer 'error' events that are fired *before* the peer is emitted in
      // a 'peer' event.
      function onError (err) {
        self.client.emit('warning', new Error(`Connection error: ${err.message}`))
        peer.destroy()
      }
  
      // Once the peer is emitted in a 'peer' event, then it's the consumer's
      // responsibility to listen for errors, so the listeners are removed here.
      function onConnect () {
        peer.removeListener('error', onError)
        peer.removeListener('connect', onConnect)
      }
    }
  }
  
  WebSocketTracker.prototype.DEFAULT_ANNOUNCE_INTERVAL = 30 * 1000 // 30 seconds
  // Normally this shouldn't be accessed but is occasionally useful
  WebSocketTracker._socketPool = socketPool
  
  function noop () {}
  
  module.exports = WebSocketTracker
  
  },{"../common":5,"./tracker":3,"debug":9,"randombytes":19,"simple-peer":37,"simple-websocket":40}],5:[function(require,module,exports){
  (function (Buffer){(function (){
  /**
   * Functions/constants needed by both the client and server.
   */
  
  exports.DEFAULT_ANNOUNCE_PEERS = 50
  exports.MAX_ANNOUNCE_PEERS = 82
  
  exports.binaryToHex = function (str) {
    if (typeof str !== 'string') {
      str = String(str)
    }
    return Buffer.from(str, 'binary').toString('hex')
  }
  
  exports.hexToBinary = function (str) {
    if (typeof str !== 'string') {
      str = String(str)
    }
    return Buffer.from(str, 'hex').toString('binary')
  }
  
  var config = require('./common-node')
  Object.assign(exports, config)
  
  }).call(this)}).call(this,require("buffer").Buffer)
  
  },{"./common-node":6,"buffer":7}],6:[function(require,module,exports){
  
  },{}],7:[function(require,module,exports){
  (function (Buffer){(function (){
  /*!
   * The buffer module from node.js, for the browser.
   *
   * @author   Feross Aboukhadijeh <https://feross.org>
   * @license  MIT
   */
  /* eslint-disable no-proto */
  
  'use strict'
  
  var base64 = require('base64-js')
  var ieee754 = require('ieee754')
  
  exports.Buffer = Buffer
  exports.SlowBuffer = SlowBuffer
  exports.INSPECT_MAX_BYTES = 50
  
  var K_MAX_LENGTH = 0x7fffffff
  exports.kMaxLength = K_MAX_LENGTH
  
  /**
   * If `Buffer.TYPED_ARRAY_SUPPORT`:
   *   === true    Use Uint8Array implementation (fastest)
   *   === false   Print warning and recommend using `buffer` v4.x which has an Object
   *               implementation (most compatible, even IE6)
   *
   * Browsers that support typed arrays are IE 10+, Firefox 4+, Chrome 7+, Safari 5.1+,
   * Opera 11.6+, iOS 4.2+.
   *
   * We report that the browser does not support typed arrays if the are not subclassable
   * using __proto__. Firefox 4-29 lacks support for adding new properties to `Uint8Array`
   * (See: https://bugzilla.mozilla.org/show_bug.cgi?id=695438). IE 10 lacks support
   * for __proto__ and has a buggy typed array implementation.
   */
  Buffer.TYPED_ARRAY_SUPPORT = typedArraySupport()
  
  if (!Buffer.TYPED_ARRAY_SUPPORT && typeof console !== 'undefined' &&
      typeof console.error === 'function') {
    console.error(
      'This browser lacks typed array (Uint8Array) support which is required by ' +
      '`buffer` v5.x. Use `buffer` v4.x if you require old browser support.'
    )
  }
  
  function typedArraySupport () {
    // Can typed array instances can be augmented?
    try {
      var arr = new Uint8Array(1)
      arr.__proto__ = { __proto__: Uint8Array.prototype, foo: function () { return 42 } }
      return arr.foo() === 42
    } catch (e) {
      return false
    }
  }
  
  Object.defineProperty(Buffer.prototype, 'parent', {
    enumerable: true,
    get: function () {
      if (!Buffer.isBuffer(this)) return undefined
      return this.buffer
    }
  })
  
  Object.defineProperty(Buffer.prototype, 'offset', {
    enumerable: true,
    get: function () {
      if (!Buffer.isBuffer(this)) return undefined
      return this.byteOffset
    }
  })
  
  function createBuffer (length) {
    if (length > K_MAX_LENGTH) {
      throw new RangeError('The value "' + length + '" is invalid for option "size"')
    }
    // Return an augmented `Uint8Array` instance
    var buf = new Uint8Array(length)
    buf.__proto__ = Buffer.prototype
    return buf
  }
  
  /**
   * The Buffer constructor returns instances of `Uint8Array` that have their
   * prototype changed to `Buffer.prototype`. Furthermore, `Buffer` is a subclass of
   * `Uint8Array`, so the returned instances will have all the node `Buffer` methods
   * and the `Uint8Array` methods. Square bracket notation works as expected -- it
   * returns a single octet.
   *
   * The `Uint8Array` prototype remains unmodified.
   */
  
  function Buffer (arg, encodingOrOffset, length) {
    // Common case.
    if (typeof arg === 'number') {
      if (typeof encodingOrOffset === 'string') {
        throw new TypeError(
          'The "string" argument must be of type string. Received type number'
        )
      }
      return allocUnsafe(arg)
    }
    return from(arg, encodingOrOffset, length)
  }
  
  // Fix subarray() in ES2016. See: https://github.com/feross/buffer/pull/97
  if (typeof Symbol !== 'undefined' && Symbol.species != null &&
      Buffer[Symbol.species] === Buffer) {
    Object.defineProperty(Buffer, Symbol.species, {
      value: null,
      configurable: true,
      enumerable: false,
      writable: false
    })
  }
  
  Buffer.poolSize = 8192 // not used by this implementation
  
  function from (value, encodingOrOffset, length) {
    if (typeof value === 'string') {
      return fromString(value, encodingOrOffset)
    }
  
    if (ArrayBuffer.isView(value)) {
      return fromArrayLike(value)
    }
  
    if (value == null) {
      throw TypeError(
        'The first argument must be one of type string, Buffer, ArrayBuffer, Array, ' +
        'or Array-like Object. Received type ' + (typeof value)
      )
    }
  
    if (isInstance(value, ArrayBuffer) ||
        (value && isInstance(value.buffer, ArrayBuffer))) {
      return fromArrayBuffer(value, encodingOrOffset, length)
    }
  
    if (typeof value === 'number') {
      throw new TypeError(
        'The "value" argument must not be of type number. Received type number'
      )
    }
  
    var valueOf = value.valueOf && value.valueOf()
    if (valueOf != null && valueOf !== value) {
      return Buffer.from(valueOf, encodingOrOffset, length)
    }
  
    var b = fromObject(value)
    if (b) return b
  
    if (typeof Symbol !== 'undefined' && Symbol.toPrimitive != null &&
        typeof value[Symbol.toPrimitive] === 'function') {
      return Buffer.from(
        value[Symbol.toPrimitive]('string'), encodingOrOffset, length
      )
    }
  
    throw new TypeError(
      'The first argument must be one of type string, Buffer, ArrayBuffer, Array, ' +
      'or Array-like Object. Received type ' + (typeof value)
    )
  }
  
  /**
   * Functionally equivalent to Buffer(arg, encoding) but throws a TypeError
   * if value is a number.
   * Buffer.from(str[, encoding])
   * Buffer.from(array)
   * Buffer.from(buffer)
   * Buffer.from(arrayBuffer[, byteOffset[, length]])
   **/
  Buffer.from = function (value, encodingOrOffset, length) {
    return from(value, encodingOrOffset, length)
  }
  
  // Note: Change prototype *after* Buffer.from is defined to workaround Chrome bug:
  // https://github.com/feross/buffer/pull/148
  Buffer.prototype.__proto__ = Uint8Array.prototype
  Buffer.__proto__ = Uint8Array
  
  function assertSize (size) {
    if (typeof size !== 'number') {
      throw new TypeError('"size" argument must be of type number')
    } else if (size < 0) {
      throw new RangeError('The value "' + size + '" is invalid for option "size"')
    }
  }
  
  function alloc (size, fill, encoding) {
    assertSize(size)
    if (size <= 0) {
      return createBuffer(size)
    }
    if (fill !== undefined) {
      // Only pay attention to encoding if it's a string. This
      // prevents accidentally sending in a number that would
      // be interpretted as a start offset.
      return typeof encoding === 'string'
        ? createBuffer(size).fill(fill, encoding)
        : createBuffer(size).fill(fill)
    }
    return createBuffer(size)
  }
  
  /**
   * Creates a new filled Buffer instance.
   * alloc(size[, fill[, encoding]])
   **/
  Buffer.alloc = function (size, fill, encoding) {
    return alloc(size, fill, encoding)
  }
  
  function allocUnsafe (size) {
    assertSize(size)
    return createBuffer(size < 0 ? 0 : checked(size) | 0)
  }
  
  /**
   * Equivalent to Buffer(num), by default creates a non-zero-filled Buffer instance.
   * */
  Buffer.allocUnsafe = function (size) {
    return allocUnsafe(size)
  }
  /**
   * Equivalent to SlowBuffer(num), by default creates a non-zero-filled Buffer instance.
   */
  Buffer.allocUnsafeSlow = function (size) {
    return allocUnsafe(size)
  }
  
  function fromString (string, encoding) {
    if (typeof encoding !== 'string' || encoding === '') {
      encoding = 'utf8'
    }
  
    if (!Buffer.isEncoding(encoding)) {
      throw new TypeError('Unknown encoding: ' + encoding)
    }
  
    var length = byteLength(string, encoding) | 0
    var buf = createBuffer(length)
  
    var actual = buf.write(string, encoding)
  
    if (actual !== length) {
      // Writing a hex string, for example, that contains invalid characters will
      // cause everything after the first invalid character to be ignored. (e.g.
      // 'abxxcd' will be treated as 'ab')
      buf = buf.slice(0, actual)
    }
  
    return buf
  }
  
  function fromArrayLike (array) {
    var length = array.length < 0 ? 0 : checked(array.length) | 0
    var buf = createBuffer(length)
    for (var i = 0; i < length; i += 1) {
      buf[i] = array[i] & 255
    }
    return buf
  }
  
  function fromArrayBuffer (array, byteOffset, length) {
    if (byteOffset < 0 || array.byteLength < byteOffset) {
      throw new RangeError('"offset" is outside of buffer bounds')
    }
  
    if (array.byteLength < byteOffset + (length || 0)) {
      throw new RangeError('"length" is outside of buffer bounds')
    }
  
    var buf
    if (byteOffset === undefined && length === undefined) {
      buf = new Uint8Array(array)
    } else if (length === undefined) {
      buf = new Uint8Array(array, byteOffset)
    } else {
      buf = new Uint8Array(array, byteOffset, length)
    }
  
    // Return an augmented `Uint8Array` instance
    buf.__proto__ = Buffer.prototype
    return buf
  }
  
  function fromObject (obj) {
    if (Buffer.isBuffer(obj)) {
      var len = checked(obj.length) | 0
      var buf = createBuffer(len)
  
      if (buf.length === 0) {
        return buf
      }
  
      obj.copy(buf, 0, 0, len)
      return buf
    }
  
    if (obj.length !== undefined) {
      if (typeof obj.length !== 'number' || numberIsNaN(obj.length)) {
        return createBuffer(0)
      }
      return fromArrayLike(obj)
    }
  
    if (obj.type === 'Buffer' && Array.isArray(obj.data)) {
      return fromArrayLike(obj.data)
    }
  }
  
  function checked (length) {
    // Note: cannot use `length < K_MAX_LENGTH` here because that fails when
    // length is NaN (which is otherwise coerced to zero.)
    if (length >= K_MAX_LENGTH) {
      throw new RangeError('Attempt to allocate Buffer larger than maximum ' +
                           'size: 0x' + K_MAX_LENGTH.toString(16) + ' bytes')
    }
    return length | 0
  }
  
  function SlowBuffer (length) {
    if (+length != length) { // eslint-disable-line eqeqeq
      length = 0
    }
    return Buffer.alloc(+length)
  }
  
  Buffer.isBuffer = function isBuffer (b) {
    return b != null && b._isBuffer === true &&
      b !== Buffer.prototype // so Buffer.isBuffer(Buffer.prototype) will be false
  }
  
  Buffer.compare = function compare (a, b) {
    if (isInstance(a, Uint8Array)) a = Buffer.from(a, a.offset, a.byteLength)
    if (isInstance(b, Uint8Array)) b = Buffer.from(b, b.offset, b.byteLength)
    if (!Buffer.isBuffer(a) || !Buffer.isBuffer(b)) {
      throw new TypeError(
        'The "buf1", "buf2" arguments must be one of type Buffer or Uint8Array'
      )
    }
  
    if (a === b) return 0
  
    var x = a.length
    var y = b.length
  
    for (var i = 0, len = Math.min(x, y); i < len; ++i) {
      if (a[i] !== b[i]) {
        x = a[i]
        y = b[i]
        break
      }
    }
  
    if (x < y) return -1
    if (y < x) return 1
    return 0
  }
  
  Buffer.isEncoding = function isEncoding (encoding) {
    switch (String(encoding).toLowerCase()) {
      case 'hex':
      case 'utf8':
      case 'utf-8':
      case 'ascii':
      case 'latin1':
      case 'binary':
      case 'base64':
      case 'ucs2':
      case 'ucs-2':
      case 'utf16le':
      case 'utf-16le':
        return true
      default:
        return false
    }
  }
  
  Buffer.concat = function concat (list, length) {
    if (!Array.isArray(list)) {
      throw new TypeError('"list" argument must be an Array of Buffers')
    }
  
    if (list.length === 0) {
      return Buffer.alloc(0)
    }
  
    var i
    if (length === undefined) {
      length = 0
      for (i = 0; i < list.length; ++i) {
        length += list[i].length
      }
    }
  
    var buffer = Buffer.allocUnsafe(length)
    var pos = 0
    for (i = 0; i < list.length; ++i) {
      var buf = list[i]
      if (isInstance(buf, Uint8Array)) {
        buf = Buffer.from(buf)
      }
      if (!Buffer.isBuffer(buf)) {
        throw new TypeError('"list" argument must be an Array of Buffers')
      }
      buf.copy(buffer, pos)
      pos += buf.length
    }
    return buffer
  }
  
  function byteLength (string, encoding) {
    if (Buffer.isBuffer(string)) {
      return string.length
    }
    if (ArrayBuffer.isView(string) || isInstance(string, ArrayBuffer)) {
      return string.byteLength
    }
    if (typeof string !== 'string') {
      throw new TypeError(
        'The "string" argument must be one of type string, Buffer, or ArrayBuffer. ' +
        'Received type ' + typeof string
      )
    }
  
    var len = string.length
    var mustMatch = (arguments.length > 2 && arguments[2] === true)
    if (!mustMatch && len === 0) return 0
  
    // Use a for loop to avoid recursion
    var loweredCase = false
    for (;;) {
      switch (encoding) {
        case 'ascii':
        case 'latin1':
        case 'binary':
          return len
        case 'utf8':
        case 'utf-8':
          return utf8ToBytes(string).length
        case 'ucs2':
        case 'ucs-2':
        case 'utf16le':
        case 'utf-16le':
          return len * 2
        case 'hex':
          return len >>> 1
        case 'base64':
          return base64ToBytes(string).length
        default:
          if (loweredCase) {
            return mustMatch ? -1 : utf8ToBytes(string).length // assume utf8
          }
          encoding = ('' + encoding).toLowerCase()
          loweredCase = true
      }
    }
  }
  Buffer.byteLength = byteLength
  
  function slowToString (encoding, start, end) {
    var loweredCase = false
  
    // No need to verify that "this.length <= MAX_UINT32" since it's a read-only
    // property of a typed array.
  
    // This behaves neither like String nor Uint8Array in that we set start/end
    // to their upper/lower bounds if the value passed is out of range.
    // undefined is handled specially as per ECMA-262 6th Edition,
    // Section 13.3.3.7 Runtime Semantics: KeyedBindingInitialization.
    if (start === undefined || start < 0) {
      start = 0
    }
    // Return early if start > this.length. Done here to prevent potential uint32
    // coercion fail below.
    if (start > this.length) {
      return ''
    }
  
    if (end === undefined || end > this.length) {
      end = this.length
    }
  
    if (end <= 0) {
      return ''
    }
  
    // Force coersion to uint32. This will also coerce falsey/NaN values to 0.
    end >>>= 0
    start >>>= 0
  
    if (end <= start) {
      return ''
    }
  
    if (!encoding) encoding = 'utf8'
  
    while (true) {
      switch (encoding) {
        case 'hex':
          return hexSlice(this, start, end)
  
        case 'utf8':
        case 'utf-8':
          return utf8Slice(this, start, end)
  
        case 'ascii':
          return asciiSlice(this, start, end)
  
        case 'latin1':
        case 'binary':
          return latin1Slice(this, start, end)
  
        case 'base64':
          return base64Slice(this, start, end)
  
        case 'ucs2':
        case 'ucs-2':
        case 'utf16le':
        case 'utf-16le':
          return utf16leSlice(this, start, end)
  
        default:
          if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding)
          encoding = (encoding + '').toLowerCase()
          loweredCase = true
      }
    }
  }
  
  // This property is used by `Buffer.isBuffer` (and the `is-buffer` npm package)
  // to detect a Buffer instance. It's not possible to use `instanceof Buffer`
  // reliably in a browserify context because there could be multiple different
  // copies of the 'buffer' package in use. This method works even for Buffer
  // instances that were created from another copy of the `buffer` package.
  // See: https://github.com/feross/buffer/issues/154
  Buffer.prototype._isBuffer = true
  
  function swap (b, n, m) {
    var i = b[n]
    b[n] = b[m]
    b[m] = i
  }
  
  Buffer.prototype.swap16 = function swap16 () {
    var len = this.length
    if (len % 2 !== 0) {
      throw new RangeError('Buffer size must be a multiple of 16-bits')
    }
    for (var i = 0; i < len; i += 2) {
      swap(this, i, i + 1)
    }
    return this
  }
  
  Buffer.prototype.swap32 = function swap32 () {
    var len = this.length
    if (len % 4 !== 0) {
      throw new RangeError('Buffer size must be a multiple of 32-bits')
    }
    for (var i = 0; i < len; i += 4) {
      swap(this, i, i + 3)
      swap(this, i + 1, i + 2)
    }
    return this
  }
  
  Buffer.prototype.swap64 = function swap64 () {
    var len = this.length
    if (len % 8 !== 0) {
      throw new RangeError('Buffer size must be a multiple of 64-bits')
    }
    for (var i = 0; i < len; i += 8) {
      swap(this, i, i + 7)
      swap(this, i + 1, i + 6)
      swap(this, i + 2, i + 5)
      swap(this, i + 3, i + 4)
    }
    return this
  }
  
  Buffer.prototype.toString = function toString () {
    var length = this.length
    if (length === 0) return ''
    if (arguments.length === 0) return utf8Slice(this, 0, length)
    return slowToString.apply(this, arguments)
  }
  
  Buffer.prototype.toLocaleString = Buffer.prototype.toString
  
  Buffer.prototype.equals = function equals (b) {
    if (!Buffer.isBuffer(b)) throw new TypeError('Argument must be a Buffer')
    if (this === b) return true
    return Buffer.compare(this, b) === 0
  }
  
  Buffer.prototype.inspect = function inspect () {
    var str = ''
    var max = exports.INSPECT_MAX_BYTES
    str = this.toString('hex', 0, max).replace(/(.{2})/g, '$1 ').trim()
    if (this.length > max) str += ' ... '
    return '<Buffer ' + str + '>'
  }
  
  Buffer.prototype.compare = function compare (target, start, end, thisStart, thisEnd) {
    if (isInstance(target, Uint8Array)) {
      target = Buffer.from(target, target.offset, target.byteLength)
    }
    if (!Buffer.isBuffer(target)) {
      throw new TypeError(
        'The "target" argument must be one of type Buffer or Uint8Array. ' +
        'Received type ' + (typeof target)
      )
    }
  
    if (start === undefined) {
      start = 0
    }
    if (end === undefined) {
      end = target ? target.length : 0
    }
    if (thisStart === undefined) {
      thisStart = 0
    }
    if (thisEnd === undefined) {
      thisEnd = this.length
    }
  
    if (start < 0 || end > target.length || thisStart < 0 || thisEnd > this.length) {
      throw new RangeError('out of range index')
    }
  
    if (thisStart >= thisEnd && start >= end) {
      return 0
    }
    if (thisStart >= thisEnd) {
      return -1
    }
    if (start >= end) {
      return 1
    }
  
    start >>>= 0
    end >>>= 0
    thisStart >>>= 0
    thisEnd >>>= 0
  
    if (this === target) return 0
  
    var x = thisEnd - thisStart
    var y = end - start
    var len = Math.min(x, y)
  
    var thisCopy = this.slice(thisStart, thisEnd)
    var targetCopy = target.slice(start, end)
  
    for (var i = 0; i < len; ++i) {
      if (thisCopy[i] !== targetCopy[i]) {
        x = thisCopy[i]
        y = targetCopy[i]
        break
      }
    }
  
    if (x < y) return -1
    if (y < x) return 1
    return 0
  }
  
  // Finds either the first index of `val` in `buffer` at offset >= `byteOffset`,
  // OR the last index of `val` in `buffer` at offset <= `byteOffset`.
  //
  // Arguments:
  // - buffer - a Buffer to search
  // - val - a string, Buffer, or number
  // - byteOffset - an index into `buffer`; will be clamped to an int32
  // - encoding - an optional encoding, relevant is val is a string
  // - dir - true for indexOf, false for lastIndexOf
  function bidirectionalIndexOf (buffer, val, byteOffset, encoding, dir) {
    // Empty buffer means no match
    if (buffer.length === 0) return -1
  
    // Normalize byteOffset
    if (typeof byteOffset === 'string') {
      encoding = byteOffset
      byteOffset = 0
    } else if (byteOffset > 0x7fffffff) {
      byteOffset = 0x7fffffff
    } else if (byteOffset < -0x80000000) {
      byteOffset = -0x80000000
    }
    byteOffset = +byteOffset // Coerce to Number.
    if (numberIsNaN(byteOffset)) {
      // byteOffset: it it's undefined, null, NaN, "foo", etc, search whole buffer
      byteOffset = dir ? 0 : (buffer.length - 1)
    }
  
    // Normalize byteOffset: negative offsets start from the end of the buffer
    if (byteOffset < 0) byteOffset = buffer.length + byteOffset
    if (byteOffset >= buffer.length) {
      if (dir) return -1
      else byteOffset = buffer.length - 1
    } else if (byteOffset < 0) {
      if (dir) byteOffset = 0
      else return -1
    }
  
    // Normalize val
    if (typeof val === 'string') {
      val = Buffer.from(val, encoding)
    }
  
    // Finally, search either indexOf (if dir is true) or lastIndexOf
    if (Buffer.isBuffer(val)) {
      // Special case: looking for empty string/buffer always fails
      if (val.length === 0) {
        return -1
      }
      return arrayIndexOf(buffer, val, byteOffset, encoding, dir)
    } else if (typeof val === 'number') {
      val = val & 0xFF // Search for a byte value [0-255]
      if (typeof Uint8Array.prototype.indexOf === 'function') {
        if (dir) {
          return Uint8Array.prototype.indexOf.call(buffer, val, byteOffset)
        } else {
          return Uint8Array.prototype.lastIndexOf.call(buffer, val, byteOffset)
        }
      }
      return arrayIndexOf(buffer, [ val ], byteOffset, encoding, dir)
    }
  
    throw new TypeError('val must be string, number or Buffer')
  }
  
  function arrayIndexOf (arr, val, byteOffset, encoding, dir) {
    var indexSize = 1
    var arrLength = arr.length
    var valLength = val.length
  
    if (encoding !== undefined) {
      encoding = String(encoding).toLowerCase()
      if (encoding === 'ucs2' || encoding === 'ucs-2' ||
          encoding === 'utf16le' || encoding === 'utf-16le') {
        if (arr.length < 2 || val.length < 2) {
          return -1
        }
        indexSize = 2
        arrLength /= 2
        valLength /= 2
        byteOffset /= 2
      }
    }
  
    function read (buf, i) {
      if (indexSize === 1) {
        return buf[i]
      } else {
        return buf.readUInt16BE(i * indexSize)
      }
    }
  
    var i
    if (dir) {
      var foundIndex = -1
      for (i = byteOffset; i < arrLength; i++) {
        if (read(arr, i) === read(val, foundIndex === -1 ? 0 : i - foundIndex)) {
          if (foundIndex === -1) foundIndex = i
          if (i - foundIndex + 1 === valLength) return foundIndex * indexSize
        } else {
          if (foundIndex !== -1) i -= i - foundIndex
          foundIndex = -1
        }
      }
    } else {
      if (byteOffset + valLength > arrLength) byteOffset = arrLength - valLength
      for (i = byteOffset; i >= 0; i--) {
        var found = true
        for (var j = 0; j < valLength; j++) {
          if (read(arr, i + j) !== read(val, j)) {
            found = false
            break
          }
        }
        if (found) return i
      }
    }
  
    return -1
  }
  
  Buffer.prototype.includes = function includes (val, byteOffset, encoding) {
    return this.indexOf(val, byteOffset, encoding) !== -1
  }
  
  Buffer.prototype.indexOf = function indexOf (val, byteOffset, encoding) {
    return bidirectionalIndexOf(this, val, byteOffset, encoding, true)
  }
  
  Buffer.prototype.lastIndexOf = function lastIndexOf (val, byteOffset, encoding) {
    return bidirectionalIndexOf(this, val, byteOffset, encoding, false)
  }
  
  function hexWrite (buf, string, offset, length) {
    offset = Number(offset) || 0
    var remaining = buf.length - offset
    if (!length) {
      length = remaining
    } else {
      length = Number(length)
      if (length > remaining) {
        length = remaining
      }
    }
  
    var strLen = string.length
  
    if (length > strLen / 2) {
      length = strLen / 2
    }
    for (var i = 0; i < length; ++i) {
      var parsed = parseInt(string.substr(i * 2, 2), 16)
      if (numberIsNaN(parsed)) return i
      buf[offset + i] = parsed
    }
    return i
  }
  
  function utf8Write (buf, string, offset, length) {
    return blitBuffer(utf8ToBytes(string, buf.length - offset), buf, offset, length)
  }
  
  function asciiWrite (buf, string, offset, length) {
    return blitBuffer(asciiToBytes(string), buf, offset, length)
  }
  
  function latin1Write (buf, string, offset, length) {
    return asciiWrite(buf, string, offset, length)
  }
  
  function base64Write (buf, string, offset, length) {
    return blitBuffer(base64ToBytes(string), buf, offset, length)
  }
  
  function ucs2Write (buf, string, offset, length) {
    return blitBuffer(utf16leToBytes(string, buf.length - offset), buf, offset, length)
  }
  
  Buffer.prototype.write = function write (string, offset, length, encoding) {
    // Buffer#write(string)
    if (offset === undefined) {
      encoding = 'utf8'
      length = this.length
      offset = 0
    // Buffer#write(string, encoding)
    } else if (length === undefined && typeof offset === 'string') {
      encoding = offset
      length = this.length
      offset = 0
    // Buffer#write(string, offset[, length][, encoding])
    } else if (isFinite(offset)) {
      offset = offset >>> 0
      if (isFinite(length)) {
        length = length >>> 0
        if (encoding === undefined) encoding = 'utf8'
      } else {
        encoding = length
        length = undefined
      }
    } else {
      throw new Error(
        'Buffer.write(string, encoding, offset[, length]) is no longer supported'
      )
    }
  
    var remaining = this.length - offset
    if (length === undefined || length > remaining) length = remaining
  
    if ((string.length > 0 && (length < 0 || offset < 0)) || offset > this.length) {
      throw new RangeError('Attempt to write outside buffer bounds')
    }
  
    if (!encoding) encoding = 'utf8'
  
    var loweredCase = false
    for (;;) {
      switch (encoding) {
        case 'hex':
          return hexWrite(this, string, offset, length)
  
        case 'utf8':
        case 'utf-8':
          return utf8Write(this, string, offset, length)
  
        case 'ascii':
          return asciiWrite(this, string, offset, length)
  
        case 'latin1':
        case 'binary':
          return latin1Write(this, string, offset, length)
  
        case 'base64':
          // Warning: maxLength not taken into account in base64Write
          return base64Write(this, string, offset, length)
  
        case 'ucs2':
        case 'ucs-2':
        case 'utf16le':
        case 'utf-16le':
          return ucs2Write(this, string, offset, length)
  
        default:
          if (loweredCase) throw new TypeError('Unknown encoding: ' + encoding)
          encoding = ('' + encoding).toLowerCase()
          loweredCase = true
      }
    }
  }
  
  Buffer.prototype.toJSON = function toJSON () {
    return {
      type: 'Buffer',
      data: Array.prototype.slice.call(this._arr || this, 0)
    }
  }
  
  function base64Slice (buf, start, end) {
    if (start === 0 && end === buf.length) {
      return base64.fromByteArray(buf)
    } else {
      return base64.fromByteArray(buf.slice(start, end))
    }
  }
  
  function utf8Slice (buf, start, end) {
    end = Math.min(buf.length, end)
    var res = []
  
    var i = start
    while (i < end) {
      var firstByte = buf[i]
      var codePoint = null
      var bytesPerSequence = (firstByte > 0xEF) ? 4
        : (firstByte > 0xDF) ? 3
          : (firstByte > 0xBF) ? 2
            : 1
  
      if (i + bytesPerSequence <= end) {
        var secondByte, thirdByte, fourthByte, tempCodePoint
  
        switch (bytesPerSequence) {
          case 1:
            if (firstByte < 0x80) {
              codePoint = firstByte
            }
            break
          case 2:
            secondByte = buf[i + 1]
            if ((secondByte & 0xC0) === 0x80) {
              tempCodePoint = (firstByte & 0x1F) << 0x6 | (secondByte & 0x3F)
              if (tempCodePoint > 0x7F) {
                codePoint = tempCodePoint
              }
            }
            break
          case 3:
            secondByte = buf[i + 1]
            thirdByte = buf[i + 2]
            if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80) {
              tempCodePoint = (firstByte & 0xF) << 0xC | (secondByte & 0x3F) << 0x6 | (thirdByte & 0x3F)
              if (tempCodePoint > 0x7FF && (tempCodePoint < 0xD800 || tempCodePoint > 0xDFFF)) {
                codePoint = tempCodePoint
              }
            }
            break
          case 4:
            secondByte = buf[i + 1]
            thirdByte = buf[i + 2]
            fourthByte = buf[i + 3]
            if ((secondByte & 0xC0) === 0x80 && (thirdByte & 0xC0) === 0x80 && (fourthByte & 0xC0) === 0x80) {
              tempCodePoint = (firstByte & 0xF) << 0x12 | (secondByte & 0x3F) << 0xC | (thirdByte & 0x3F) << 0x6 | (fourthByte & 0x3F)
              if (tempCodePoint > 0xFFFF && tempCodePoint < 0x110000) {
                codePoint = tempCodePoint
              }
            }
        }
      }
  
      if (codePoint === null) {
        // we did not generate a valid codePoint so insert a
        // replacement char (U+FFFD) and advance only 1 byte
        codePoint = 0xFFFD
        bytesPerSequence = 1
      } else if (codePoint > 0xFFFF) {
        // encode to utf16 (surrogate pair dance)
        codePoint -= 0x10000
        res.push(codePoint >>> 10 & 0x3FF | 0xD800)
        codePoint = 0xDC00 | codePoint & 0x3FF
      }
  
      res.push(codePoint)
      i += bytesPerSequence
    }
  
    return decodeCodePointsArray(res)
  }
  
  // Based on http://stackoverflow.com/a/22747272/680742, the browser with
  // the lowest limit is Chrome, with 0x10000 args.
  // We go 1 magnitude less, for safety
  var MAX_ARGUMENTS_LENGTH = 0x1000
  
  function decodeCodePointsArray (codePoints) {
    var len = codePoints.length
    if (len <= MAX_ARGUMENTS_LENGTH) {
      return String.fromCharCode.apply(String, codePoints) // avoid extra slice()
    }
  
    // Decode in chunks to avoid "call stack size exceeded".
    var res = ''
    var i = 0
    while (i < len) {
      res += String.fromCharCode.apply(
        String,
        codePoints.slice(i, i += MAX_ARGUMENTS_LENGTH)
      )
    }
    return res
  }
  
  function asciiSlice (buf, start, end) {
    var ret = ''
    end = Math.min(buf.length, end)
  
    for (var i = start; i < end; ++i) {
      ret += String.fromCharCode(buf[i] & 0x7F)
    }
    return ret
  }
  
  function latin1Slice (buf, start, end) {
    var ret = ''
    end = Math.min(buf.length, end)
  
    for (var i = start; i < end; ++i) {
      ret += String.fromCharCode(buf[i])
    }
    return ret
  }
  
  function hexSlice (buf, start, end) {
    var len = buf.length
  
    if (!start || start < 0) start = 0
    if (!end || end < 0 || end > len) end = len
  
    var out = ''
    for (var i = start; i < end; ++i) {
      out += toHex(buf[i])
    }
    return out
  }
  
  function utf16leSlice (buf, start, end) {
    var bytes = buf.slice(start, end)
    var res = ''
    for (var i = 0; i < bytes.length; i += 2) {
      res += String.fromCharCode(bytes[i] + (bytes[i + 1] * 256))
    }
    return res
  }
  
  Buffer.prototype.slice = function slice (start, end) {
    var len = this.length
    start = ~~start
    end = end === undefined ? len : ~~end
  
    if (start < 0) {
      start += len
      if (start < 0) start = 0
    } else if (start > len) {
      start = len
    }
  
    if (end < 0) {
      end += len
      if (end < 0) end = 0
    } else if (end > len) {
      end = len
    }
  
    if (end < start) end = start
  
    var newBuf = this.subarray(start, end)
    // Return an augmented `Uint8Array` instance
    newBuf.__proto__ = Buffer.prototype
    return newBuf
  }
  
  /*
   * Need to make sure that buffer isn't trying to write out of bounds.
   */
  function checkOffset (offset, ext, length) {
    if ((offset % 1) !== 0 || offset < 0) throw new RangeError('offset is not uint')
    if (offset + ext > length) throw new RangeError('Trying to access beyond buffer length')
  }
  
  Buffer.prototype.readUIntLE = function readUIntLE (offset, byteLength, noAssert) {
    offset = offset >>> 0
    byteLength = byteLength >>> 0
    if (!noAssert) checkOffset(offset, byteLength, this.length)
  
    var val = this[offset]
    var mul = 1
    var i = 0
    while (++i < byteLength && (mul *= 0x100)) {
      val += this[offset + i] * mul
    }
  
    return val
  }
  
  Buffer.prototype.readUIntBE = function readUIntBE (offset, byteLength, noAssert) {
    offset = offset >>> 0
    byteLength = byteLength >>> 0
    if (!noAssert) {
      checkOffset(offset, byteLength, this.length)
    }
  
    var val = this[offset + --byteLength]
    var mul = 1
    while (byteLength > 0 && (mul *= 0x100)) {
      val += this[offset + --byteLength] * mul
    }
  
    return val
  }
  
  Buffer.prototype.readUInt8 = function readUInt8 (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 1, this.length)
    return this[offset]
  }
  
  Buffer.prototype.readUInt16LE = function readUInt16LE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 2, this.length)
    return this[offset] | (this[offset + 1] << 8)
  }
  
  Buffer.prototype.readUInt16BE = function readUInt16BE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 2, this.length)
    return (this[offset] << 8) | this[offset + 1]
  }
  
  Buffer.prototype.readUInt32LE = function readUInt32LE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 4, this.length)
  
    return ((this[offset]) |
        (this[offset + 1] << 8) |
        (this[offset + 2] << 16)) +
        (this[offset + 3] * 0x1000000)
  }
  
  Buffer.prototype.readUInt32BE = function readUInt32BE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 4, this.length)
  
    return (this[offset] * 0x1000000) +
      ((this[offset + 1] << 16) |
      (this[offset + 2] << 8) |
      this[offset + 3])
  }
  
  Buffer.prototype.readIntLE = function readIntLE (offset, byteLength, noAssert) {
    offset = offset >>> 0
    byteLength = byteLength >>> 0
    if (!noAssert) checkOffset(offset, byteLength, this.length)
  
    var val = this[offset]
    var mul = 1
    var i = 0
    while (++i < byteLength && (mul *= 0x100)) {
      val += this[offset + i] * mul
    }
    mul *= 0x80
  
    if (val >= mul) val -= Math.pow(2, 8 * byteLength)
  
    return val
  }
  
  Buffer.prototype.readIntBE = function readIntBE (offset, byteLength, noAssert) {
    offset = offset >>> 0
    byteLength = byteLength >>> 0
    if (!noAssert) checkOffset(offset, byteLength, this.length)
  
    var i = byteLength
    var mul = 1
    var val = this[offset + --i]
    while (i > 0 && (mul *= 0x100)) {
      val += this[offset + --i] * mul
    }
    mul *= 0x80
  
    if (val >= mul) val -= Math.pow(2, 8 * byteLength)
  
    return val
  }
  
  Buffer.prototype.readInt8 = function readInt8 (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 1, this.length)
    if (!(this[offset] & 0x80)) return (this[offset])
    return ((0xff - this[offset] + 1) * -1)
  }
  
  Buffer.prototype.readInt16LE = function readInt16LE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 2, this.length)
    var val = this[offset] | (this[offset + 1] << 8)
    return (val & 0x8000) ? val | 0xFFFF0000 : val
  }
  
  Buffer.prototype.readInt16BE = function readInt16BE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 2, this.length)
    var val = this[offset + 1] | (this[offset] << 8)
    return (val & 0x8000) ? val | 0xFFFF0000 : val
  }
  
  Buffer.prototype.readInt32LE = function readInt32LE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 4, this.length)
  
    return (this[offset]) |
      (this[offset + 1] << 8) |
      (this[offset + 2] << 16) |
      (this[offset + 3] << 24)
  }
  
  Buffer.prototype.readInt32BE = function readInt32BE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 4, this.length)
  
    return (this[offset] << 24) |
      (this[offset + 1] << 16) |
      (this[offset + 2] << 8) |
      (this[offset + 3])
  }
  
  Buffer.prototype.readFloatLE = function readFloatLE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 4, this.length)
    return ieee754.read(this, offset, true, 23, 4)
  }
  
  Buffer.prototype.readFloatBE = function readFloatBE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 4, this.length)
    return ieee754.read(this, offset, false, 23, 4)
  }
  
  Buffer.prototype.readDoubleLE = function readDoubleLE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 8, this.length)
    return ieee754.read(this, offset, true, 52, 8)
  }
  
  Buffer.prototype.readDoubleBE = function readDoubleBE (offset, noAssert) {
    offset = offset >>> 0
    if (!noAssert) checkOffset(offset, 8, this.length)
    return ieee754.read(this, offset, false, 52, 8)
  }
  
  function checkInt (buf, value, offset, ext, max, min) {
    if (!Buffer.isBuffer(buf)) throw new TypeError('"buffer" argument must be a Buffer instance')
    if (value > max || value < min) throw new RangeError('"value" argument is out of bounds')
    if (offset + ext > buf.length) throw new RangeError('Index out of range')
  }
  
  Buffer.prototype.writeUIntLE = function writeUIntLE (value, offset, byteLength, noAssert) {
    value = +value
    offset = offset >>> 0
    byteLength = byteLength >>> 0
    if (!noAssert) {
      var maxBytes = Math.pow(2, 8 * byteLength) - 1
      checkInt(this, value, offset, byteLength, maxBytes, 0)
    }
  
    var mul = 1
    var i = 0
    this[offset] = value & 0xFF
    while (++i < byteLength && (mul *= 0x100)) {
      this[offset + i] = (value / mul) & 0xFF
    }
  
    return offset + byteLength
  }
  
  Buffer.prototype.writeUIntBE = function writeUIntBE (value, offset, byteLength, noAssert) {
    value = +value
    offset = offset >>> 0
    byteLength = byteLength >>> 0
    if (!noAssert) {
      var maxBytes = Math.pow(2, 8 * byteLength) - 1
      checkInt(this, value, offset, byteLength, maxBytes, 0)
    }
  
    var i = byteLength - 1
    var mul = 1
    this[offset + i] = value & 0xFF
    while (--i >= 0 && (mul *= 0x100)) {
      this[offset + i] = (value / mul) & 0xFF
    }
  
    return offset + byteLength
  }
  
  Buffer.prototype.writeUInt8 = function writeUInt8 (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 1, 0xff, 0)
    this[offset] = (value & 0xff)
    return offset + 1
  }
  
  Buffer.prototype.writeUInt16LE = function writeUInt16LE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0)
    this[offset] = (value & 0xff)
    this[offset + 1] = (value >>> 8)
    return offset + 2
  }
  
  Buffer.prototype.writeUInt16BE = function writeUInt16BE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 2, 0xffff, 0)
    this[offset] = (value >>> 8)
    this[offset + 1] = (value & 0xff)
    return offset + 2
  }
  
  Buffer.prototype.writeUInt32LE = function writeUInt32LE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0)
    this[offset + 3] = (value >>> 24)
    this[offset + 2] = (value >>> 16)
    this[offset + 1] = (value >>> 8)
    this[offset] = (value & 0xff)
    return offset + 4
  }
  
  Buffer.prototype.writeUInt32BE = function writeUInt32BE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 4, 0xffffffff, 0)
    this[offset] = (value >>> 24)
    this[offset + 1] = (value >>> 16)
    this[offset + 2] = (value >>> 8)
    this[offset + 3] = (value & 0xff)
    return offset + 4
  }
  
  Buffer.prototype.writeIntLE = function writeIntLE (value, offset, byteLength, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) {
      var limit = Math.pow(2, (8 * byteLength) - 1)
  
      checkInt(this, value, offset, byteLength, limit - 1, -limit)
    }
  
    var i = 0
    var mul = 1
    var sub = 0
    this[offset] = value & 0xFF
    while (++i < byteLength && (mul *= 0x100)) {
      if (value < 0 && sub === 0 && this[offset + i - 1] !== 0) {
        sub = 1
      }
      this[offset + i] = ((value / mul) >> 0) - sub & 0xFF
    }
  
    return offset + byteLength
  }
  
  Buffer.prototype.writeIntBE = function writeIntBE (value, offset, byteLength, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) {
      var limit = Math.pow(2, (8 * byteLength) - 1)
  
      checkInt(this, value, offset, byteLength, limit - 1, -limit)
    }
  
    var i = byteLength - 1
    var mul = 1
    var sub = 0
    this[offset + i] = value & 0xFF
    while (--i >= 0 && (mul *= 0x100)) {
      if (value < 0 && sub === 0 && this[offset + i + 1] !== 0) {
        sub = 1
      }
      this[offset + i] = ((value / mul) >> 0) - sub & 0xFF
    }
  
    return offset + byteLength
  }
  
  Buffer.prototype.writeInt8 = function writeInt8 (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 1, 0x7f, -0x80)
    if (value < 0) value = 0xff + value + 1
    this[offset] = (value & 0xff)
    return offset + 1
  }
  
  Buffer.prototype.writeInt16LE = function writeInt16LE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000)
    this[offset] = (value & 0xff)
    this[offset + 1] = (value >>> 8)
    return offset + 2
  }
  
  Buffer.prototype.writeInt16BE = function writeInt16BE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 2, 0x7fff, -0x8000)
    this[offset] = (value >>> 8)
    this[offset + 1] = (value & 0xff)
    return offset + 2
  }
  
  Buffer.prototype.writeInt32LE = function writeInt32LE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000)
    this[offset] = (value & 0xff)
    this[offset + 1] = (value >>> 8)
    this[offset + 2] = (value >>> 16)
    this[offset + 3] = (value >>> 24)
    return offset + 4
  }
  
  Buffer.prototype.writeInt32BE = function writeInt32BE (value, offset, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) checkInt(this, value, offset, 4, 0x7fffffff, -0x80000000)
    if (value < 0) value = 0xffffffff + value + 1
    this[offset] = (value >>> 24)
    this[offset + 1] = (value >>> 16)
    this[offset + 2] = (value >>> 8)
    this[offset + 3] = (value & 0xff)
    return offset + 4
  }
  
  function checkIEEE754 (buf, value, offset, ext, max, min) {
    if (offset + ext > buf.length) throw new RangeError('Index out of range')
    if (offset < 0) throw new RangeError('Index out of range')
  }
  
  function writeFloat (buf, value, offset, littleEndian, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) {
      checkIEEE754(buf, value, offset, 4, 3.4028234663852886e+38, -3.4028234663852886e+38)
    }
    ieee754.write(buf, value, offset, littleEndian, 23, 4)
    return offset + 4
  }
  
  Buffer.prototype.writeFloatLE = function writeFloatLE (value, offset, noAssert) {
    return writeFloat(this, value, offset, true, noAssert)
  }
  
  Buffer.prototype.writeFloatBE = function writeFloatBE (value, offset, noAssert) {
    return writeFloat(this, value, offset, false, noAssert)
  }
  
  function writeDouble (buf, value, offset, littleEndian, noAssert) {
    value = +value
    offset = offset >>> 0
    if (!noAssert) {
      checkIEEE754(buf, value, offset, 8, 1.7976931348623157E+308, -1.7976931348623157E+308)
    }
    ieee754.write(buf, value, offset, littleEndian, 52, 8)
    return offset + 8
  }
  
  Buffer.prototype.writeDoubleLE = function writeDoubleLE (value, offset, noAssert) {
    return writeDouble(this, value, offset, true, noAssert)
  }
  
  Buffer.prototype.writeDoubleBE = function writeDoubleBE (value, offset, noAssert) {
    return writeDouble(this, value, offset, false, noAssert)
  }
  
  // copy(targetBuffer, targetStart=0, sourceStart=0, sourceEnd=buffer.length)
  Buffer.prototype.copy = function copy (target, targetStart, start, end) {
    if (!Buffer.isBuffer(target)) throw new TypeError('argument should be a Buffer')
    if (!start) start = 0
    if (!end && end !== 0) end = this.length
    if (targetStart >= target.length) targetStart = target.length
    if (!targetStart) targetStart = 0
    if (end > 0 && end < start) end = start
  
    // Copy 0 bytes; we're done
    if (end === start) return 0
    if (target.length === 0 || this.length === 0) return 0
  
    // Fatal error conditions
    if (targetStart < 0) {
      throw new RangeError('targetStart out of bounds')
    }
    if (start < 0 || start >= this.length) throw new RangeError('Index out of range')
    if (end < 0) throw new RangeError('sourceEnd out of bounds')
  
    // Are we oob?
    if (end > this.length) end = this.length
    if (target.length - targetStart < end - start) {
      end = target.length - targetStart + start
    }
  
    var len = end - start
  
    if (this === target && typeof Uint8Array.prototype.copyWithin === 'function') {
      // Use built-in when available, missing from IE11
      this.copyWithin(targetStart, start, end)
    } else if (this === target && start < targetStart && targetStart < end) {
      // descending copy from end
      for (var i = len - 1; i >= 0; --i) {
        target[i + targetStart] = this[i + start]
      }
    } else {
      Uint8Array.prototype.set.call(
        target,
        this.subarray(start, end),
        targetStart
      )
    }
  
    return len
  }
  
  // Usage:
  //    buffer.fill(number[, offset[, end]])
  //    buffer.fill(buffer[, offset[, end]])
  //    buffer.fill(string[, offset[, end]][, encoding])
  Buffer.prototype.fill = function fill (val, start, end, encoding) {
    // Handle string cases:
    if (typeof val === 'string') {
      if (typeof start === 'string') {
        encoding = start
        start = 0
        end = this.length
      } else if (typeof end === 'string') {
        encoding = end
        end = this.length
      }
      if (encoding !== undefined && typeof encoding !== 'string') {
        throw new TypeError('encoding must be a string')
      }
      if (typeof encoding === 'string' && !Buffer.isEncoding(encoding)) {
        throw new TypeError('Unknown encoding: ' + encoding)
      }
      if (val.length === 1) {
        var code = val.charCodeAt(0)
        if ((encoding === 'utf8' && code < 128) ||
            encoding === 'latin1') {
          // Fast path: If `val` fits into a single byte, use that numeric value.
          val = code
        }
      }
    } else if (typeof val === 'number') {
      val = val & 255
    }
  
    // Invalid ranges are not set to a default, so can range check early.
    if (start < 0 || this.length < start || this.length < end) {
      throw new RangeError('Out of range index')
    }
  
    if (end <= start) {
      return this
    }
  
    start = start >>> 0
    end = end === undefined ? this.length : end >>> 0
  
    if (!val) val = 0
  
    var i
    if (typeof val === 'number') {
      for (i = start; i < end; ++i) {
        this[i] = val
      }
    } else {
      var bytes = Buffer.isBuffer(val)
        ? val
        : Buffer.from(val, encoding)
      var len = bytes.length
      if (len === 0) {
        throw new TypeError('The value "' + val +
          '" is invalid for argument "value"')
      }
      for (i = 0; i < end - start; ++i) {
        this[i + start] = bytes[i % len]
      }
    }
  
    return this
  }
  
  // HELPER FUNCTIONS
  // ================
  
  var INVALID_BASE64_RE = /[^+/0-9A-Za-z-_]/g
  
  function base64clean (str) {
    // Node takes equal signs as end of the Base64 encoding
    str = str.split('=')[0]
    // Node strips out invalid characters like \n and \t from the string, base64-js does not
    str = str.trim().replace(INVALID_BASE64_RE, '')
    // Node converts strings with length < 2 to ''
    if (str.length < 2) return ''
    // Node allows for non-padded base64 strings (missing trailing ===), base64-js does not
    while (str.length % 4 !== 0) {
      str = str + '='
    }
    return str
  }
  
  function toHex (n) {
    if (n < 16) return '0' + n.toString(16)
    return n.toString(16)
  }
  
  function utf8ToBytes (string, units) {
    units = units || Infinity
    var codePoint
    var length = string.length
    var leadSurrogate = null
    var bytes = []
  
    for (var i = 0; i < length; ++i) {
      codePoint = string.charCodeAt(i)
  
      // is surrogate component
      if (codePoint > 0xD7FF && codePoint < 0xE000) {
        // last char was a lead
        if (!leadSurrogate) {
          // no lead yet
          if (codePoint > 0xDBFF) {
            // unexpected trail
            if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
            continue
          } else if (i + 1 === length) {
            // unpaired lead
            if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
            continue
          }
  
          // valid lead
          leadSurrogate = codePoint
  
          continue
        }
  
        // 2 leads in a row
        if (codePoint < 0xDC00) {
          if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
          leadSurrogate = codePoint
          continue
        }
  
        // valid surrogate pair
        codePoint = (leadSurrogate - 0xD800 << 10 | codePoint - 0xDC00) + 0x10000
      } else if (leadSurrogate) {
        // valid bmp char, but last char was a lead
        if ((units -= 3) > -1) bytes.push(0xEF, 0xBF, 0xBD)
      }
  
      leadSurrogate = null
  
      // encode utf8
      if (codePoint < 0x80) {
        if ((units -= 1) < 0) break
        bytes.push(codePoint)
      } else if (codePoint < 0x800) {
        if ((units -= 2) < 0) break
        bytes.push(
          codePoint >> 0x6 | 0xC0,
          codePoint & 0x3F | 0x80
        )
      } else if (codePoint < 0x10000) {
        if ((units -= 3) < 0) break
        bytes.push(
          codePoint >> 0xC | 0xE0,
          codePoint >> 0x6 & 0x3F | 0x80,
          codePoint & 0x3F | 0x80
        )
      } else if (codePoint < 0x110000) {
        if ((units -= 4) < 0) break
        bytes.push(
          codePoint >> 0x12 | 0xF0,
          codePoint >> 0xC & 0x3F | 0x80,
          codePoint >> 0x6 & 0x3F | 0x80,
          codePoint & 0x3F | 0x80
        )
      } else {
        throw new Error('Invalid code point')
      }
    }
  
    return bytes
  }
  
  function asciiToBytes (str) {
    var byteArray = []
    for (var i = 0; i < str.length; ++i) {
      // Node's code seems to be doing this and not & 0x7F..
      byteArray.push(str.charCodeAt(i) & 0xFF)
    }
    return byteArray
  }
  
  function utf16leToBytes (str, units) {
    var c, hi, lo
    var byteArray = []
    for (var i = 0; i < str.length; ++i) {
      if ((units -= 2) < 0) break
  
      c = str.charCodeAt(i)
      hi = c >> 8
      lo = c % 256
      byteArray.push(lo)
      byteArray.push(hi)
    }
  
    return byteArray
  }
  
  function base64ToBytes (str) {
    return base64.toByteArray(base64clean(str))
  }
  
  function blitBuffer (src, dst, offset, length) {
    for (var i = 0; i < length; ++i) {
      if ((i + offset >= dst.length) || (i >= src.length)) break
      dst[i + offset] = src[i]
    }
    return i
  }
  
  // ArrayBuffer or Uint8Array objects from other contexts (i.e. iframes) do not pass
  // the `instanceof` check but they should be treated as of that type.
  // See: https://github.com/feross/buffer/issues/166
  function isInstance (obj, type) {
    return obj instanceof type ||
      (obj != null && obj.constructor != null && obj.constructor.name != null &&
        obj.constructor.name === type.name)
  }
  function numberIsNaN (obj) {
    // For IE11 support
    return obj !== obj // eslint-disable-line no-self-compare
  }
  
  }).call(this)}).call(this,require("buffer").Buffer)
  
  },{"base64-js":2,"buffer":7,"ieee754":13}],8:[function(require,module,exports){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  var objectCreate = Object.create || objectCreatePolyfill
  var objectKeys = Object.keys || objectKeysPolyfill
  var bind = Function.prototype.bind || functionBindPolyfill
  
  function EventEmitter() {
    if (!this._events || !Object.prototype.hasOwnProperty.call(this, '_events')) {
      this._events = objectCreate(null);
      this._eventsCount = 0;
    }
  
    this._maxListeners = this._maxListeners || undefined;
  }
  module.exports = EventEmitter;
  
  // Backwards-compat with node 0.10.x
  EventEmitter.EventEmitter = EventEmitter;
  
  EventEmitter.prototype._events = undefined;
  EventEmitter.prototype._maxListeners = undefined;
  
  // By default EventEmitters will print a warning if more than 10 listeners are
  // added to it. This is a useful default which helps finding memory leaks.
  var defaultMaxListeners = 10;
  
  var hasDefineProperty;
  try {
    var o = {};
    if (Object.defineProperty) Object.defineProperty(o, 'x', { value: 0 });
    hasDefineProperty = o.x === 0;
  } catch (err) { hasDefineProperty = false }
  if (hasDefineProperty) {
    Object.defineProperty(EventEmitter, 'defaultMaxListeners', {
      enumerable: true,
      get: function() {
        return defaultMaxListeners;
      },
      set: function(arg) {
        // check whether the input is a positive number (whose value is zero or
        // greater and not a NaN).
        if (typeof arg !== 'number' || arg < 0 || arg !== arg)
          throw new TypeError('"defaultMaxListeners" must be a positive number');
        defaultMaxListeners = arg;
      }
    });
  } else {
    EventEmitter.defaultMaxListeners = defaultMaxListeners;
  }
  
  // Obviously not all Emitters should be limited to 10. This function allows
  // that to be increased. Set to zero for unlimited.
  EventEmitter.prototype.setMaxListeners = function setMaxListeners(n) {
    if (typeof n !== 'number' || n < 0 || isNaN(n))
      throw new TypeError('"n" argument must be a positive number');
    this._maxListeners = n;
    return this;
  };
  
  function $getMaxListeners(that) {
    if (that._maxListeners === undefined)
      return EventEmitter.defaultMaxListeners;
    return that._maxListeners;
  }
  
  EventEmitter.prototype.getMaxListeners = function getMaxListeners() {
    return $getMaxListeners(this);
  };
  
  // These standalone emit* functions are used to optimize calling of event
  // handlers for fast cases because emit() itself often has a variable number of
  // arguments and can be deoptimized because of that. These functions always have
  // the same number of arguments and thus do not get deoptimized, so the code
  // inside them can execute faster.
  function emitNone(handler, isFn, self) {
    if (isFn)
      handler.call(self);
    else {
      var len = handler.length;
      var listeners = arrayClone(handler, len);
      for (var i = 0; i < len; ++i)
        listeners[i].call(self);
    }
  }
  function emitOne(handler, isFn, self, arg1) {
    if (isFn)
      handler.call(self, arg1);
    else {
      var len = handler.length;
      var listeners = arrayClone(handler, len);
      for (var i = 0; i < len; ++i)
        listeners[i].call(self, arg1);
    }
  }
  function emitTwo(handler, isFn, self, arg1, arg2) {
    if (isFn)
      handler.call(self, arg1, arg2);
    else {
      var len = handler.length;
      var listeners = arrayClone(handler, len);
      for (var i = 0; i < len; ++i)
        listeners[i].call(self, arg1, arg2);
    }
  }
  function emitThree(handler, isFn, self, arg1, arg2, arg3) {
    if (isFn)
      handler.call(self, arg1, arg2, arg3);
    else {
      var len = handler.length;
      var listeners = arrayClone(handler, len);
      for (var i = 0; i < len; ++i)
        listeners[i].call(self, arg1, arg2, arg3);
    }
  }
  
  function emitMany(handler, isFn, self, args) {
    if (isFn)
      handler.apply(self, args);
    else {
      var len = handler.length;
      var listeners = arrayClone(handler, len);
      for (var i = 0; i < len; ++i)
        listeners[i].apply(self, args);
    }
  }
  
  EventEmitter.prototype.emit = function emit(type) {
    var er, handler, len, args, i, events;
    var doError = (type === 'error');
  
    events = this._events;
    if (events)
      doError = (doError && events.error == null);
    else if (!doError)
      return false;
  
    // If there is no 'error' event listener then throw.
    if (doError) {
      if (arguments.length > 1)
        er = arguments[1];
      if (er instanceof Error) {
        throw er; // Unhandled 'error' event
      } else {
        // At least give some kind of context to the user
        var err = new Error('Unhandled "error" event. (' + er + ')');
        err.context = er;
        throw err;
      }
      return false;
    }
  
    handler = events[type];
  
    if (!handler)
      return false;
  
    var isFn = typeof handler === 'function';
    len = arguments.length;
    switch (len) {
        // fast cases
      case 1:
        emitNone(handler, isFn, this);
        break;
      case 2:
        emitOne(handler, isFn, this, arguments[1]);
        break;
      case 3:
        emitTwo(handler, isFn, this, arguments[1], arguments[2]);
        break;
      case 4:
        emitThree(handler, isFn, this, arguments[1], arguments[2], arguments[3]);
        break;
        // slower
      default:
        args = new Array(len - 1);
        for (i = 1; i < len; i++)
          args[i - 1] = arguments[i];
        emitMany(handler, isFn, this, args);
    }
  
    return true;
  };
  
  function _addListener(target, type, listener, prepend) {
    var m;
    var events;
    var existing;
  
    if (typeof listener !== 'function')
      throw new TypeError('"listener" argument must be a function');
  
    events = target._events;
    if (!events) {
      events = target._events = objectCreate(null);
      target._eventsCount = 0;
    } else {
      // To avoid recursion in the case that type === "newListener"! Before
      // adding it to the listeners, first emit "newListener".
      if (events.newListener) {
        target.emit('newListener', type,
            listener.listener ? listener.listener : listener);
  
        // Re-assign `events` because a newListener handler could have caused the
        // this._events to be assigned to a new object
        events = target._events;
      }
      existing = events[type];
    }
  
    if (!existing) {
      // Optimize the case of one listener. Don't need the extra array object.
      existing = events[type] = listener;
      ++target._eventsCount;
    } else {
      if (typeof existing === 'function') {
        // Adding the second element, need to change to array.
        existing = events[type] =
            prepend ? [listener, existing] : [existing, listener];
      } else {
        // If we've already got an array, just append.
        if (prepend) {
          existing.unshift(listener);
        } else {
          existing.push(listener);
        }
      }
  
      // Check for listener leak
      if (!existing.warned) {
        m = $getMaxListeners(target);
        if (m && m > 0 && existing.length > m) {
          existing.warned = true;
          var w = new Error('Possible EventEmitter memory leak detected. ' +
              existing.length + ' "' + String(type) + '" listeners ' +
              'added. Use emitter.setMaxListeners() to ' +
              'increase limit.');
          w.name = 'MaxListenersExceededWarning';
          w.emitter = target;
          w.type = type;
          w.count = existing.length;
          if (typeof console === 'object' && console.warn) {
            console.warn('%s: %s', w.name, w.message);
          }
        }
      }
    }
  
    return target;
  }
  
  EventEmitter.prototype.addListener = function addListener(type, listener) {
    return _addListener(this, type, listener, false);
  };
  
  EventEmitter.prototype.on = EventEmitter.prototype.addListener;
  
  EventEmitter.prototype.prependListener =
      function prependListener(type, listener) {
        return _addListener(this, type, listener, true);
      };
  
  function onceWrapper() {
    if (!this.fired) {
      this.target.removeListener(this.type, this.wrapFn);
      this.fired = true;
      switch (arguments.length) {
        case 0:
          return this.listener.call(this.target);
        case 1:
          return this.listener.call(this.target, arguments[0]);
        case 2:
          return this.listener.call(this.target, arguments[0], arguments[1]);
        case 3:
          return this.listener.call(this.target, arguments[0], arguments[1],
              arguments[2]);
        default:
          var args = new Array(arguments.length);
          for (var i = 0; i < args.length; ++i)
            args[i] = arguments[i];
          this.listener.apply(this.target, args);
      }
    }
  }
  
  function _onceWrap(target, type, listener) {
    var state = { fired: false, wrapFn: undefined, target: target, type: type, listener: listener };
    var wrapped = bind.call(onceWrapper, state);
    wrapped.listener = listener;
    state.wrapFn = wrapped;
    return wrapped;
  }
  
  EventEmitter.prototype.once = function once(type, listener) {
    if (typeof listener !== 'function')
      throw new TypeError('"listener" argument must be a function');
    this.on(type, _onceWrap(this, type, listener));
    return this;
  };
  
  EventEmitter.prototype.prependOnceListener =
      function prependOnceListener(type, listener) {
        if (typeof listener !== 'function')
          throw new TypeError('"listener" argument must be a function');
        this.prependListener(type, _onceWrap(this, type, listener));
        return this;
      };
  
  // Emits a 'removeListener' event if and only if the listener was removed.
  EventEmitter.prototype.removeListener =
      function removeListener(type, listener) {
        var list, events, position, i, originalListener;
  
        if (typeof listener !== 'function')
          throw new TypeError('"listener" argument must be a function');
  
        events = this._events;
        if (!events)
          return this;
  
        list = events[type];
        if (!list)
          return this;
  
        if (list === listener || list.listener === listener) {
          if (--this._eventsCount === 0)
            this._events = objectCreate(null);
          else {
            delete events[type];
            if (events.removeListener)
              this.emit('removeListener', type, list.listener || listener);
          }
        } else if (typeof list !== 'function') {
          position = -1;
  
          for (i = list.length - 1; i >= 0; i--) {
            if (list[i] === listener || list[i].listener === listener) {
              originalListener = list[i].listener;
              position = i;
              break;
            }
          }
  
          if (position < 0)
            return this;
  
          if (position === 0)
            list.shift();
          else
            spliceOne(list, position);
  
          if (list.length === 1)
            events[type] = list[0];
  
          if (events.removeListener)
            this.emit('removeListener', type, originalListener || listener);
        }
  
        return this;
      };
  
  EventEmitter.prototype.removeAllListeners =
      function removeAllListeners(type) {
        var listeners, events, i;
  
        events = this._events;
        if (!events)
          return this;
  
        // not listening for removeListener, no need to emit
        if (!events.removeListener) {
          if (arguments.length === 0) {
            this._events = objectCreate(null);
            this._eventsCount = 0;
          } else if (events[type]) {
            if (--this._eventsCount === 0)
              this._events = objectCreate(null);
            else
              delete events[type];
          }
          return this;
        }
  
        // emit removeListener for all listeners on all events
        if (arguments.length === 0) {
          var keys = objectKeys(events);
          var key;
          for (i = 0; i < keys.length; ++i) {
            key = keys[i];
            if (key === 'removeListener') continue;
            this.removeAllListeners(key);
          }
          this.removeAllListeners('removeListener');
          this._events = objectCreate(null);
          this._eventsCount = 0;
          return this;
        }
  
        listeners = events[type];
  
        if (typeof listeners === 'function') {
          this.removeListener(type, listeners);
        } else if (listeners) {
          // LIFO order
          for (i = listeners.length - 1; i >= 0; i--) {
            this.removeListener(type, listeners[i]);
          }
        }
  
        return this;
      };
  
  function _listeners(target, type, unwrap) {
    var events = target._events;
  
    if (!events)
      return [];
  
    var evlistener = events[type];
    if (!evlistener)
      return [];
  
    if (typeof evlistener === 'function')
      return unwrap ? [evlistener.listener || evlistener] : [evlistener];
  
    return unwrap ? unwrapListeners(evlistener) : arrayClone(evlistener, evlistener.length);
  }
  
  EventEmitter.prototype.listeners = function listeners(type) {
    return _listeners(this, type, true);
  };
  
  EventEmitter.prototype.rawListeners = function rawListeners(type) {
    return _listeners(this, type, false);
  };
  
  EventEmitter.listenerCount = function(emitter, type) {
    if (typeof emitter.listenerCount === 'function') {
      return emitter.listenerCount(type);
    } else {
      return listenerCount.call(emitter, type);
    }
  };
  
  EventEmitter.prototype.listenerCount = listenerCount;
  function listenerCount(type) {
    var events = this._events;
  
    if (events) {
      var evlistener = events[type];
  
      if (typeof evlistener === 'function') {
        return 1;
      } else if (evlistener) {
        return evlistener.length;
      }
    }
  
    return 0;
  }
  
  EventEmitter.prototype.eventNames = function eventNames() {
    return this._eventsCount > 0 ? Reflect.ownKeys(this._events) : [];
  };
  
  // About 1.5x faster than the two-arg version of Array#splice().
  function spliceOne(list, index) {
    for (var i = index, k = i + 1, n = list.length; k < n; i += 1, k += 1)
      list[i] = list[k];
    list.pop();
  }
  
  function arrayClone(arr, n) {
    var copy = new Array(n);
    for (var i = 0; i < n; ++i)
      copy[i] = arr[i];
    return copy;
  }
  
  function unwrapListeners(arr) {
    var ret = new Array(arr.length);
    for (var i = 0; i < ret.length; ++i) {
      ret[i] = arr[i].listener || arr[i];
    }
    return ret;
  }
  
  function objectCreatePolyfill(proto) {
    var F = function() {};
    F.prototype = proto;
    return new F;
  }
  function objectKeysPolyfill(obj) {
    var keys = [];
    for (var k in obj) if (Object.prototype.hasOwnProperty.call(obj, k)) {
      keys.push(k);
    }
    return k;
  }
  function functionBindPolyfill(context) {
    var fn = this;
    return function () {
      return fn.apply(context, arguments);
    };
  }
  
  },{}],9:[function(require,module,exports){
  (function (process){(function (){
  /* eslint-env browser */
  
  /**
   * This is the web browser implementation of `debug()`.
   */
  
  exports.formatArgs = formatArgs;
  exports.save = save;
  exports.load = load;
  exports.useColors = useColors;
  exports.storage = localstorage();
  exports.destroy = (() => {
    let warned = false;
  
    return () => {
      if (!warned) {
        warned = true;
        console.warn('Instance method `debug.destroy()` is deprecated and no longer does anything. It will be removed in the next major version of `debug`.');
      }
    };
  })();
  
  /**
   * Colors.
   */
  
  exports.colors = [
    '#0000CC',
    '#0000FF',
    '#0033CC',
    '#0033FF',
    '#0066CC',
    '#0066FF',
    '#0099CC',
    '#0099FF',
    '#00CC00',
    '#00CC33',
    '#00CC66',
    '#00CC99',
    '#00CCCC',
    '#00CCFF',
    '#3300CC',
    '#3300FF',
    '#3333CC',
    '#3333FF',
    '#3366CC',
    '#3366FF',
    '#3399CC',
    '#3399FF',
    '#33CC00',
    '#33CC33',
    '#33CC66',
    '#33CC99',
    '#33CCCC',
    '#33CCFF',
    '#6600CC',
    '#6600FF',
    '#6633CC',
    '#6633FF',
    '#66CC00',
    '#66CC33',
    '#9900CC',
    '#9900FF',
    '#9933CC',
    '#9933FF',
    '#99CC00',
    '#99CC33',
    '#CC0000',
    '#CC0033',
    '#CC0066',
    '#CC0099',
    '#CC00CC',
    '#CC00FF',
    '#CC3300',
    '#CC3333',
    '#CC3366',
    '#CC3399',
    '#CC33CC',
    '#CC33FF',
    '#CC6600',
    '#CC6633',
    '#CC9900',
    '#CC9933',
    '#CCCC00',
    '#CCCC33',
    '#FF0000',
    '#FF0033',
    '#FF0066',
    '#FF0099',
    '#FF00CC',
    '#FF00FF',
    '#FF3300',
    '#FF3333',
    '#FF3366',
    '#FF3399',
    '#FF33CC',
    '#FF33FF',
    '#FF6600',
    '#FF6633',
    '#FF9900',
    '#FF9933',
    '#FFCC00',
    '#FFCC33'
  ];
  
  /**
   * Currently only WebKit-based Web Inspectors, Firefox >= v31,
   * and the Firebug extension (any Firefox version) are known
   * to support "%c" CSS customizations.
   *
   * TODO: add a `localStorage` variable to explicitly enable/disable colors
   */
  
  // eslint-disable-next-line complexity
  function useColors() {
    // NB: In an Electron preload script, document will be defined but not fully
    // initialized. Since we know we're in Chrome, we'll just detect this case
    // explicitly
    if (typeof window !== 'undefined' && window.process && (window.process.type === 'renderer' || window.process.__nwjs)) {
      return true;
    }
  
    // Internet Explorer and Edge do not support colors.
    if (typeof navigator !== 'undefined' && navigator.userAgent && navigator.userAgent.toLowerCase().match(/(edge|trident)\/(\d+)/)) {
      return false;
    }
  
    // Is webkit? http://stackoverflow.com/a/16459606/376773
    // document is undefined in react-native: https://github.com/facebook/react-native/pull/1632
    return (typeof document !== 'undefined' && document.documentElement && document.documentElement.style && document.documentElement.style.WebkitAppearance) ||
      // Is firebug? http://stackoverflow.com/a/398120/376773
      (typeof window !== 'undefined' && window.console && (window.console.firebug || (window.console.exception && window.console.table))) ||
      // Is firefox >= v31?
      // https://developer.mozilla.org/en-US/docs/Tools/Web_Console#Styling_messages
      (typeof navigator !== 'undefined' && navigator.userAgent && navigator.userAgent.toLowerCase().match(/firefox\/(\d+)/) && parseInt(RegExp.$1, 10) >= 31) ||
      // Double check webkit in userAgent just in case we are in a worker
      (typeof navigator !== 'undefined' && navigator.userAgent && navigator.userAgent.toLowerCase().match(/applewebkit\/(\d+)/));
  }
  
  /**
   * Colorize log arguments if enabled.
   *
   * @api public
   */
  
  function formatArgs(args) {
    args[0] = (this.useColors ? '%c' : '') +
      this.namespace +
      (this.useColors ? ' %c' : ' ') +
      args[0] +
      (this.useColors ? '%c ' : ' ') +
      '+' + module.exports.humanize(this.diff);
  
    if (!this.useColors) {
      return;
    }
  
    const c = 'color: ' + this.color;
    args.splice(1, 0, c, 'color: inherit');
  
    // The final "%c" is somewhat tricky, because there could be other
    // arguments passed either before or after the %c, so we need to
    // figure out the correct index to insert the CSS into
    let index = 0;
    let lastC = 0;
    args[0].replace(/%[a-zA-Z%]/g, match => {
      if (match === '%%') {
        return;
      }
      index++;
      if (match === '%c') {
        // We only are interested in the *last* %c
        // (the user may have provided their own)
        lastC = index;
      }
    });
  
    args.splice(lastC, 0, c);
  }
  
  /**
   * Invokes `console.debug()` when available.
   * No-op when `console.debug` is not a "function".
   * If `console.debug` is not available, falls back
   * to `console.log`.
   *
   * @api public
   */
  exports.log = console.debug || console.log || (() => {});
  
  /**
   * Save `namespaces`.
   *
   * @param {String} namespaces
   * @api private
   */
  function save(namespaces) {
    try {
      if (namespaces) {
        exports.storage.setItem('debug', namespaces);
      } else {
        exports.storage.removeItem('debug');
      }
    } catch (error) {
      // Swallow
      // XXX (@Qix-) should we be logging these?
    }
  }
  
  /**
   * Load `namespaces`.
   *
   * @return {String} returns the previously persisted debug modes
   * @api private
   */
  function load() {
    let r;
    try {
      r = exports.storage.getItem('debug');
    } catch (error) {
      // Swallow
      // XXX (@Qix-) should we be logging these?
    }
  
    // If debug isn't set in LS, and we're in Electron, try to load $DEBUG
    if (!r && typeof process !== 'undefined' && 'env' in process) {
      r = process.env.DEBUG;
    }
  
    return r;
  }
  
  /**
   * Localstorage attempts to return the localstorage.
   *
   * This is necessary because safari throws
   * when a user disables cookies/localstorage
   * and you attempt to access it.
   *
   * @return {LocalStorage}
   * @api private
   */
  
  function localstorage() {
    try {
      // TVMLKit (Apple TV JS Runtime) does not have a window object, just localStorage in the global context
      // The Browser also has localStorage in the global context.
      return localStorage;
    } catch (error) {
      // Swallow
      // XXX (@Qix-) should we be logging these?
    }
  }
  
  module.exports = require('./common')(exports);
  
  const {formatters} = module.exports;
  
  /**
   * Map %j to `JSON.stringify()`, since no Web Inspectors do that by default.
   */
  
  formatters.j = function (v) {
    try {
      return JSON.stringify(v);
    } catch (error) {
      return '[UnexpectedJSONParseError]: ' + error.message;
    }
  };
  
  }).call(this)}).call(this,require('_process'))
  
  },{"./common":10,"_process":17}],10:[function(require,module,exports){
  
  /**
   * This is the common logic for both the Node.js and web browser
   * implementations of `debug()`.
   */
  
  function setup(env) {
    createDebug.debug = createDebug;
    createDebug.default = createDebug;
    createDebug.coerce = coerce;
    createDebug.disable = disable;
    createDebug.enable = enable;
    createDebug.enabled = enabled;
    createDebug.humanize = require('ms');
    createDebug.destroy = destroy;
  
    Object.keys(env).forEach(key => {
      createDebug[key] = env[key];
    });
  
    /**
    * The currently active debug mode names, and names to skip.
    */
  
    createDebug.names = [];
    createDebug.skips = [];
  
    /**
    * Map of special "%n" handling functions, for the debug "format" argument.
    *
    * Valid key names are a single, lower or upper-case letter, i.e. "n" and "N".
    */
    createDebug.formatters = {};
  
    /**
    * Selects a color for a debug namespace
    * @param {String} namespace The namespace string for the for the debug instance to be colored
    * @return {Number|String} An ANSI color code for the given namespace
    * @api private
    */
    function selectColor(namespace) {
      let hash = 0;
  
      for (let i = 0; i < namespace.length; i++) {
        hash = ((hash << 5) - hash) + namespace.charCodeAt(i);
        hash |= 0; // Convert to 32bit integer
      }
  
      return createDebug.colors[Math.abs(hash) % createDebug.colors.length];
    }
    createDebug.selectColor = selectColor;
  
    /**
    * Create a debugger with the given `namespace`.
    *
    * @param {String} namespace
    * @return {Function}
    * @api public
    */
    function createDebug(namespace) {
      let prevTime;
      let enableOverride = null;
  
      function debug(...args) {
        // Disabled?
        if (!debug.enabled) {
          return;
        }
  
        const self = debug;
  
        // Set `diff` timestamp
        const curr = Number(new Date());
        const ms = curr - (prevTime || curr);
        self.diff = ms;
        self.prev = prevTime;
        self.curr = curr;
        prevTime = curr;
  
        args[0] = createDebug.coerce(args[0]);
  
        if (typeof args[0] !== 'string') {
          // Anything else let's inspect with %O
          args.unshift('%O');
        }
  
        // Apply any `formatters` transformations
        let index = 0;
        args[0] = args[0].replace(/%([a-zA-Z%])/g, (match, format) => {
          // If we encounter an escaped % then don't increase the array index
          if (match === '%%') {
            return '%';
          }
          index++;
          const formatter = createDebug.formatters[format];
          if (typeof formatter === 'function') {
            const val = args[index];
            match = formatter.call(self, val);
  
            // Now we need to remove `args[index]` since it's inlined in the `format`
            args.splice(index, 1);
            index--;
          }
          return match;
        });
  
        // Apply env-specific formatting (colors, etc.)
        createDebug.formatArgs.call(self, args);
  
        const logFn = self.log || createDebug.log;
        logFn.apply(self, args);
      }
  
      debug.namespace = namespace;
      debug.useColors = createDebug.useColors();
      debug.color = createDebug.selectColor(namespace);
      debug.extend = extend;
      debug.destroy = createDebug.destroy; // XXX Temporary. Will be removed in the next major release.
  
      Object.defineProperty(debug, 'enabled', {
        enumerable: true,
        configurable: false,
        get: () => enableOverride === null ? createDebug.enabled(namespace) : enableOverride,
        set: v => {
          enableOverride = v;
        }
      });
  
      // Env-specific initialization logic for debug instances
      if (typeof createDebug.init === 'function') {
        createDebug.init(debug);
      }
  
      return debug;
    }
  
    function extend(namespace, delimiter) {
      const newDebug = createDebug(this.namespace + (typeof delimiter === 'undefined' ? ':' : delimiter) + namespace);
      newDebug.log = this.log;
      return newDebug;
    }
  
    /**
    * Enables a debug mode by namespaces. This can include modes
    * separated by a colon and wildcards.
    *
    * @param {String} namespaces
    * @api public
    */
    function enable(namespaces) {
      createDebug.save(namespaces);
  
      createDebug.names = [];
      createDebug.skips = [];
  
      let i;
      const split = (typeof namespaces === 'string' ? namespaces : '').split(/[\s,]+/);
      const len = split.length;
  
      for (i = 0; i < len; i++) {
        if (!split[i]) {
          // ignore empty strings
          continue;
        }
  
        namespaces = split[i].replace(/\*/g, '.*?');
  
        if (namespaces[0] === '-') {
          createDebug.skips.push(new RegExp('^' + namespaces.substr(1) + '$'));
        } else {
          createDebug.names.push(new RegExp('^' + namespaces + '$'));
        }
      }
    }
  
    /**
    * Disable debug output.
    *
    * @return {String} namespaces
    * @api public
    */
    function disable() {
      const namespaces = [
        ...createDebug.names.map(toNamespace),
        ...createDebug.skips.map(toNamespace).map(namespace => '-' + namespace)
      ].join(',');
      createDebug.enable('');
      return namespaces;
    }
  
    /**
    * Returns true if the given mode name is enabled, false otherwise.
    *
    * @param {String} name
    * @return {Boolean}
    * @api public
    */
    function enabled(name) {
      if (name[name.length - 1] === '*') {
        return true;
      }
  
      let i;
      let len;
  
      for (i = 0, len = createDebug.skips.length; i < len; i++) {
        if (createDebug.skips[i].test(name)) {
          return false;
        }
      }
  
      for (i = 0, len = createDebug.names.length; i < len; i++) {
        if (createDebug.names[i].test(name)) {
          return true;
        }
      }
  
      return false;
    }
  
    /**
    * Convert regexp to namespace
    *
    * @param {RegExp} regxep
    * @return {String} namespace
    * @api private
    */
    function toNamespace(regexp) {
      return regexp.toString()
        .substring(2, regexp.toString().length - 2)
        .replace(/\.\*\?$/, '*');
    }
  
    /**
    * Coerce `val`.
    *
    * @param {Mixed} val
    * @return {Mixed}
    * @api private
    */
    function coerce(val) {
      if (val instanceof Error) {
        return val.stack || val.message;
      }
      return val;
    }
  
    /**
    * XXX DO NOT USE. This is a temporary stub function.
    * XXX It WILL be removed in the next major release.
    */
    function destroy() {
      console.warn('Instance method `debug.destroy()` is deprecated and no longer does anything. It will be removed in the next major version of `debug`.');
    }
  
    createDebug.enable(createDebug.load());
  
    return createDebug;
  }
  
  module.exports = setup;
  
  },{"ms":15}],11:[function(require,module,exports){
  'use strict';
  
  function assign(obj, props) {
      for (const key in props) {
          Object.defineProperty(obj, key, {
              value: props[key],
              enumerable: true,
              configurable: true,
          });
      }
  
      return obj;
  }
  
  function createError(err, code, props) {
      if (!err || typeof err === 'string') {
          throw new TypeError('Please pass an Error to err-code');
      }
  
      if (!props) {
          props = {};
      }
  
      if (typeof code === 'object') {
          props = code;
          code = undefined;
      }
  
      if (code != null) {
          props.code = code;
      }
  
      try {
          return assign(err, props);
      } catch (_) {
          props.message = err.message;
          props.stack = err.stack;
  
          const ErrClass = function () {};
  
          ErrClass.prototype = Object.create(Object.getPrototypeOf(err));
  
          return assign(new ErrClass(), props);
      }
  }
  
  module.exports = createError;
  
  },{}],12:[function(require,module,exports){
  // originally pulled out of simple-peer
  
  module.exports = function getBrowserRTC () {
    if (typeof globalThis === 'undefined') return null
    var wrtc = {
      RTCPeerConnection: globalThis.RTCPeerConnection || globalThis.mozRTCPeerConnection ||
        globalThis.webkitRTCPeerConnection,
      RTCSessionDescription: globalThis.RTCSessionDescription ||
        globalThis.mozRTCSessionDescription || globalThis.webkitRTCSessionDescription,
      RTCIceCandidate: globalThis.RTCIceCandidate || globalThis.mozRTCIceCandidate ||
        globalThis.webkitRTCIceCandidate
    }
    if (!wrtc.RTCPeerConnection) return null
    return wrtc
  }
  
  },{}],13:[function(require,module,exports){
  /*! ieee754. BSD-3-Clause License. Feross Aboukhadijeh <https://feross.org/opensource> */
  exports.read = function (buffer, offset, isLE, mLen, nBytes) {
    var e, m
    var eLen = (nBytes * 8) - mLen - 1
    var eMax = (1 << eLen) - 1
    var eBias = eMax >> 1
    var nBits = -7
    var i = isLE ? (nBytes - 1) : 0
    var d = isLE ? -1 : 1
    var s = buffer[offset + i]
  
    i += d
  
    e = s & ((1 << (-nBits)) - 1)
    s >>= (-nBits)
    nBits += eLen
    for (; nBits > 0; e = (e * 256) + buffer[offset + i], i += d, nBits -= 8) {}
  
    m = e & ((1 << (-nBits)) - 1)
    e >>= (-nBits)
    nBits += mLen
    for (; nBits > 0; m = (m * 256) + buffer[offset + i], i += d, nBits -= 8) {}
  
    if (e === 0) {
      e = 1 - eBias
    } else if (e === eMax) {
      return m ? NaN : ((s ? -1 : 1) * Infinity)
    } else {
      m = m + Math.pow(2, mLen)
      e = e - eBias
    }
    return (s ? -1 : 1) * m * Math.pow(2, e - mLen)
  }
  
  exports.write = function (buffer, value, offset, isLE, mLen, nBytes) {
    var e, m, c
    var eLen = (nBytes * 8) - mLen - 1
    var eMax = (1 << eLen) - 1
    var eBias = eMax >> 1
    var rt = (mLen === 23 ? Math.pow(2, -24) - Math.pow(2, -77) : 0)
    var i = isLE ? 0 : (nBytes - 1)
    var d = isLE ? 1 : -1
    var s = value < 0 || (value === 0 && 1 / value < 0) ? 1 : 0
  
    value = Math.abs(value)
  
    if (isNaN(value) || value === Infinity) {
      m = isNaN(value) ? 1 : 0
      e = eMax
    } else {
      e = Math.floor(Math.log(value) / Math.LN2)
      if (value * (c = Math.pow(2, -e)) < 1) {
        e--
        c *= 2
      }
      if (e + eBias >= 1) {
        value += rt / c
      } else {
        value += rt * Math.pow(2, 1 - eBias)
      }
      if (value * c >= 2) {
        e++
        c /= 2
      }
  
      if (e + eBias >= eMax) {
        m = 0
        e = eMax
      } else if (e + eBias >= 1) {
        m = ((value * c) - 1) * Math.pow(2, mLen)
        e = e + eBias
      } else {
        m = value * Math.pow(2, eBias - 1) * Math.pow(2, mLen)
        e = 0
      }
    }
  
    for (; mLen >= 8; buffer[offset + i] = m & 0xff, i += d, m /= 256, mLen -= 8) {}
  
    e = (e << mLen) | m
    eLen += mLen
    for (; eLen > 0; buffer[offset + i] = e & 0xff, i += d, e /= 256, eLen -= 8) {}
  
    buffer[offset + i - d] |= s * 128
  }
  
  },{}],14:[function(require,module,exports){
  if (typeof Object.create === 'function') {
    // implementation from standard node.js 'util' module
    module.exports = function inherits(ctor, superCtor) {
      if (superCtor) {
        ctor.super_ = superCtor
        ctor.prototype = Object.create(superCtor.prototype, {
          constructor: {
            value: ctor,
            enumerable: false,
            writable: true,
            configurable: true
          }
        })
      }
    };
  } else {
    // old school shim for old browsers
    module.exports = function inherits(ctor, superCtor) {
      if (superCtor) {
        ctor.super_ = superCtor
        var TempCtor = function () {}
        TempCtor.prototype = superCtor.prototype
        ctor.prototype = new TempCtor()
        ctor.prototype.constructor = ctor
      }
    }
  }
  
  },{}],15:[function(require,module,exports){
  /**
   * Helpers.
   */
  
  var s = 1000;
  var m = s * 60;
  var h = m * 60;
  var d = h * 24;
  var w = d * 7;
  var y = d * 365.25;
  
  /**
   * Parse or format the given `val`.
   *
   * Options:
   *
   *  - `long` verbose formatting [false]
   *
   * @param {String|Number} val
   * @param {Object} [options]
   * @throws {Error} throw an error if val is not a non-empty string or a number
   * @return {String|Number}
   * @api public
   */
  
  module.exports = function(val, options) {
    options = options || {};
    var type = typeof val;
    if (type === 'string' && val.length > 0) {
      return parse(val);
    } else if (type === 'number' && isFinite(val)) {
      return options.long ? fmtLong(val) : fmtShort(val);
    }
    throw new Error(
      'val is not a non-empty string or a valid number. val=' +
        JSON.stringify(val)
    );
  };
  
  /**
   * Parse the given `str` and return milliseconds.
   *
   * @param {String} str
   * @return {Number}
   * @api private
   */
  
  function parse(str) {
    str = String(str);
    if (str.length > 100) {
      return;
    }
    var match = /^(-?(?:\d+)?\.?\d+) *(milliseconds?|msecs?|ms|seconds?|secs?|s|minutes?|mins?|m|hours?|hrs?|h|days?|d|weeks?|w|years?|yrs?|y)?$/i.exec(
      str
    );
    if (!match) {
      return;
    }
    var n = parseFloat(match[1]);
    var type = (match[2] || 'ms').toLowerCase();
    switch (type) {
      case 'years':
      case 'year':
      case 'yrs':
      case 'yr':
      case 'y':
        return n * y;
      case 'weeks':
      case 'week':
      case 'w':
        return n * w;
      case 'days':
      case 'day':
      case 'd':
        return n * d;
      case 'hours':
      case 'hour':
      case 'hrs':
      case 'hr':
      case 'h':
        return n * h;
      case 'minutes':
      case 'minute':
      case 'mins':
      case 'min':
      case 'm':
        return n * m;
      case 'seconds':
      case 'second':
      case 'secs':
      case 'sec':
      case 's':
        return n * s;
      case 'milliseconds':
      case 'millisecond':
      case 'msecs':
      case 'msec':
      case 'ms':
        return n;
      default:
        return undefined;
    }
  }
  
  /**
   * Short format for `ms`.
   *
   * @param {Number} ms
   * @return {String}
   * @api private
   */
  
  function fmtShort(ms) {
    var msAbs = Math.abs(ms);
    if (msAbs >= d) {
      return Math.round(ms / d) + 'd';
    }
    if (msAbs >= h) {
      return Math.round(ms / h) + 'h';
    }
    if (msAbs >= m) {
      return Math.round(ms / m) + 'm';
    }
    if (msAbs >= s) {
      return Math.round(ms / s) + 's';
    }
    return ms + 'ms';
  }
  
  /**
   * Long format for `ms`.
   *
   * @param {Number} ms
   * @return {String}
   * @api private
   */
  
  function fmtLong(ms) {
    var msAbs = Math.abs(ms);
    if (msAbs >= d) {
      return plural(ms, msAbs, d, 'day');
    }
    if (msAbs >= h) {
      return plural(ms, msAbs, h, 'hour');
    }
    if (msAbs >= m) {
      return plural(ms, msAbs, m, 'minute');
    }
    if (msAbs >= s) {
      return plural(ms, msAbs, s, 'second');
    }
    return ms + ' ms';
  }
  
  /**
   * Pluralization helper.
   */
  
  function plural(ms, msAbs, n, name) {
    var isPlural = msAbs >= n * 1.5;
    return Math.round(ms / n) + ' ' + name + (isPlural ? 's' : '');
  }
  
  },{}],16:[function(require,module,exports){
  (function (Buffer){(function (){
  /**
   * Peer 2 Peer WebRTC connections with WebTorrent Trackers as signalling server
   * Copyright Subin Siby <mail@subinsb.com>, 2020
   * Licensed under MIT
   */
  
  const WebSocketTracker = require('bittorrent-tracker/lib/client/websocket-tracker')
  const randombytes = require('randombytes')
  const EventEmitter = require('events')
  const sha1 = require('simple-sha1')
  const debug = require('debug')('p2pt')
  
  /**
   * This character would be prepended to easily identify JSON msgs
   */
  const JSON_MESSAGE_IDENTIFIER = '^'
  
  /**
   * WebRTC data channel limit beyond which data is split into chunks
   * Chose 16KB considering Chromium
   * https://developer.mozilla.org/en-US/docs/Web/API/WebRTC_API/Using_data_channels#Concerns_with_large_messages
   */
  const MAX_MESSAGE_LENGTH = 16000
  
  class P2PT extends EventEmitter {
    /**
     *
     * @param array announceURLs List of announce tracker URLs
     * @param string identifierString Identifier used to discover peers in the network
     */
    constructor (announceURLs = [], identifierString = '') {
      super()
  
      this.announceURLs = announceURLs
      this.trackers = {}
      this.peers = {}
      this.msgChunks = {}
      this.responseWaiting = {}
  
      if (identifierString) { this.setIdentifier(identifierString) }
  
      this._peerIdBuffer = randombytes(20)
      this._peerId = this._peerIdBuffer.toString('hex')
      this._peerIdBinary = this._peerIdBuffer.toString('binary')
  
      debug('my peer id: ' + this._peerId)
    }
  
    /**
     * Set the identifier string used to discover peers in the network
     * @param string identifierString
     */
    setIdentifier (identifierString) {
      this.identifierString = identifierString
      this.infoHash = sha1.sync(identifierString).toLowerCase()
      this._infoHashBuffer = Buffer.from(this.infoHash, 'hex')
      this._infoHashBinary = this._infoHashBuffer.toString('binary')
    }
  
    /**
     * Connect to network and start discovering peers
     */
    start () {
      this.on('peer', peer => {
        let newpeer = false
        if (!this.peers[peer.id]) {
          newpeer = true
          this.peers[peer.id] = {}
          this.responseWaiting[peer.id] = {}
        }
  
        peer.on('connect', () => {
          /**
           * Multiple data channels to one peer is possible
           * The `peer` object actually refers to a peer with a data channel. Even though it may have same `id` (peerID) property, the data channel will be different. Different trackers giving the same "peer" will give the `peer` object with different channels.
           * We will store all channels as backups in case any one of them fails
           * A peer is removed if all data channels become unavailable
           */
          this.peers[peer.id][peer.channelName] = peer
  
          if (newpeer) {
            this.emit('peerconnect', peer)
          }
        })
  
        peer.on('data', data => {
          this.emit('data', peer, data)
  
          data = data.toString()
  
          debug('got a message from ' + peer.id)
  
          if (data[0] === JSON_MESSAGE_IDENTIFIER) {
            try {
              data = JSON.parse(data.slice(1))
  
              // A respond function
              peer.respond = this._peerRespond(peer, data.id)
  
              let msg = this._chunkHandler(data)
  
              // msg fully retrieved
              if (msg !== false) {
                if (data.o) {
                  msg = JSON.parse(msg)
                }
  
                /**
                 * If there's someone waiting for a response, call them
                 */
                if (this.responseWaiting[peer.id][data.id]) {
                  this.responseWaiting[peer.id][data.id]([peer, msg])
                  delete this.responseWaiting[peer.id][data.id]
                } else {
                  this.emit('msg', peer, msg)
                }
                this._destroyChunks(data.id)
              }
            } catch (e) {
              console.log(e)
            }
          }
        })
  
        peer.on('error', err => {
          this._removePeer(peer)
          debug('Error in connection : ' + err)
        })
  
        peer.on('close', () => {
          this._removePeer(peer)
          debug('Connection closed with ' + peer.id)
        })
      })
  
      // Tracker responded to the announce request
      this.on('update', response => {
        const tracker = this.trackers[this.announceURLs.indexOf(response.announce)]
  
        this.emit(
          'trackerconnect',
          tracker,
          this.getTrackerStats()
        )
      })
  
      // Errors in tracker connection
      this.on('warning', err => {
        this.emit(
          'trackerwarning',
          err,
          this.getTrackerStats()
        )
      })
  
      this._fetchPeers()
    }
  
    /**
     * Add a tracker
     * @param string announceURL Tracker Announce URL
     */
    addTracker (announceURL) {
      if (this.announceURLs.indexOf(announceURL) !== -1) {
        throw new Error('Tracker already added')
      }
  
      const key = this.announceURLs.push(announceURL)
  
      this.trackers[key] = new WebSocketTracker(this, announceURL)
      this.trackers[key].announce(this._defaultAnnounceOpts())
    }
  
    /**
     * Remove a tracker without destroying peers
     */
    removeTracker (announceURL) {
      const key = this.announceURLs.indexOf(announceURL)
  
      if (key === -1) {
        throw new Error('Tracker does not exist')
      }
  
      // hack to not destroy peers
      this.trackers[key].peers = []
      this.trackers[key].destroy()
  
      delete this.trackers[key]
      delete this.announceURLs[key]
    }
  
    /**
     * Remove a peer from the list if all channels are closed
     * @param integer id Peer ID
     */
    _removePeer (peer) {
      if (!this.peers[peer.id]) { return false }
  
      delete this.peers[peer.id][peer.channelName]
  
      // All data channels are gone. Peer lost
      if (Object.keys(this.peers[peer.id]).length === 0) {
        this.emit('peerclose', peer)
  
        delete this.responseWaiting[peer.id]
        delete this.peers[peer.id]
      }
    }
  
    /**
     * Send a msg and get response for it
     * @param Peer peer simple-peer object to send msg to
     * @param string msg Message to send
     * @param integer msgID ID of message if it's a response to a previous message
     */
    send (peer, msg, msgID = '') {
      return new Promise((resolve, reject) => {
        const data = {
          id: msgID !== '' ? msgID : Math.floor(Math.random() * 100000 + 100000),
          msg
        }
  
        if (typeof msg === 'object') {
          data.msg = JSON.stringify(msg)
          data.o = 1 // indicating object
        }
  
        try {
          /**
           * Maybe peer channel is closed, so use a different channel if available
           * Array should atleast have one channel, otherwise peer connection is closed
           */
          if (!peer.connected) {
            for (const index in this.peers[peer.id]) {
              peer = this.peers[peer.id][index]
  
              if (peer.connected) break
            }
          }
  
          if (!this.responseWaiting[peer.id]) {
            this.responseWaiting[peer.id] = {}
          }
          this.responseWaiting[peer.id][data.id] = resolve
        } catch (e) {
          return reject(Error('Connection to peer closed' + e))
        }
  
        let chunks = 0
        let remaining = ''
        while (data.msg.length > 0) {
          data.c = chunks
  
          remaining = data.msg.slice(MAX_MESSAGE_LENGTH)
          data.msg = data.msg.slice(0, MAX_MESSAGE_LENGTH)
  
          if (!remaining) { data.last = true }
  
          peer.send(JSON_MESSAGE_IDENTIFIER + JSON.stringify(data))
  
          data.msg = remaining
          chunks++
        }
  
        debug('sent a message to ' + peer.id)
      })
    }
  
    /**
     * Request more peers
     */
    requestMorePeers () {
      return new Promise(resolve => {
        for (const key in this.trackers) {
          this.trackers[key].announce(this._defaultAnnounceOpts())
        }
        resolve(this.peers)
      })
    }
  
    /**
     * Get basic stats about tracker connections
     */
    getTrackerStats () {
      let connectedCount = 0
      for (const key in this.trackers) {
        if (this.trackers[key].socket && this.trackers[key].socket.connected) {
          connectedCount++
        }
      }
  
      return {
        connected: connectedCount,
        total: this.announceURLs.length
      }
    }
  
    /**
     * Destroy object
     */
    destroy () {
      let key
      for (key in this.peers) {
        for (const key2 in this.peers[key]) {
          this.peers[key][key2].destroy()
        }
      }
      for (key in this.trackers) {
        this.trackers[key].destroy()
      }
    }
  
    /**
     * A custom function binded on Peer object to easily respond back to message
     * @param Peer peer Peer to send msg to
     * @param integer msgID Message ID
     */
    _peerRespond (peer, msgID) {
      return msg => {
        return this.send(peer, msg, msgID)
      }
    }
  
    /**
     * Handle msg chunks. Returns false until the last chunk is received. Finally returns the entire msg
     * @param object data
     */
    _chunkHandler (data) {
      if (!this.msgChunks[data.id]) {
        this.msgChunks[data.id] = []
      }
  
      this.msgChunks[data.id][data.c] = data.msg
  
      if (data.last) {
        const completeMsg = this.msgChunks[data.id].join('')
        return completeMsg
      } else {
        return false
      }
    }
  
    /**
     * Remove all stored chunks of a particular message
     * @param integer msgID Message ID
     */
    _destroyChunks (msgID) {
      delete this.msgChunks[msgID]
    }
  
    /**
     * Default announce options
     * @param object opts Options
     */
    _defaultAnnounceOpts (opts = {}) {
      if (opts.numwant == null) opts.numwant = 50
  
      if (opts.uploaded == null) opts.uploaded = 0
      if (opts.downloaded == null) opts.downloaded = 0
  
      return opts
    }
  
    /**
     * Initialize trackers and fetch peers
     */
    _fetchPeers () {
      for (const key in this.announceURLs) {
        this.trackers[key] = new WebSocketTracker(this, this.announceURLs[key])
        this.trackers[key].announce(this._defaultAnnounceOpts())
      }
    }
  }
  
  module.exports = P2PT
  
  }).call(this)}).call(this,require("buffer").Buffer)
  
  },{"bittorrent-tracker/lib/client/websocket-tracker":4,"buffer":7,"debug":9,"events":8,"randombytes":19,"simple-sha1":38}],17:[function(require,module,exports){
  // shim for using process in browser
  var process = module.exports = {};
  
  // cached from whatever global is present so that test runners that stub it
  // don't break things.  But we need to wrap it in a try catch in case it is
  // wrapped in strict mode code which doesn't define any globals.  It's inside a
  // function because try/catches deoptimize in certain engines.
  
  var cachedSetTimeout;
  var cachedClearTimeout;
  
  function defaultSetTimout() {
      throw new Error('setTimeout has not been defined');
  }
  function defaultClearTimeout () {
      throw new Error('clearTimeout has not been defined');
  }
  (function () {
      try {
          if (typeof setTimeout === 'function') {
              cachedSetTimeout = setTimeout;
          } else {
              cachedSetTimeout = defaultSetTimout;
          }
      } catch (e) {
          cachedSetTimeout = defaultSetTimout;
      }
      try {
          if (typeof clearTimeout === 'function') {
              cachedClearTimeout = clearTimeout;
          } else {
              cachedClearTimeout = defaultClearTimeout;
          }
      } catch (e) {
          cachedClearTimeout = defaultClearTimeout;
      }
  } ())
  function runTimeout(fun) {
      if (cachedSetTimeout === setTimeout) {
          //normal enviroments in sane situations
          return setTimeout(fun, 0);
      }
      // if setTimeout wasn't available but was latter defined
      if ((cachedSetTimeout === defaultSetTimout || !cachedSetTimeout) && setTimeout) {
          cachedSetTimeout = setTimeout;
          return setTimeout(fun, 0);
      }
      try {
          // when when somebody has screwed with setTimeout but no I.E. maddness
          return cachedSetTimeout(fun, 0);
      } catch(e){
          try {
              // When we are in I.E. but the script has been evaled so I.E. doesn't trust the global object when called normally
              return cachedSetTimeout.call(null, fun, 0);
          } catch(e){
              // same as above but when it's a version of I.E. that must have the global object for 'this', hopfully our context correct otherwise it will throw a global error
              return cachedSetTimeout.call(this, fun, 0);
          }
      }
  
  
  }
  function runClearTimeout(marker) {
      if (cachedClearTimeout === clearTimeout) {
          //normal enviroments in sane situations
          return clearTimeout(marker);
      }
      // if clearTimeout wasn't available but was latter defined
      if ((cachedClearTimeout === defaultClearTimeout || !cachedClearTimeout) && clearTimeout) {
          cachedClearTimeout = clearTimeout;
          return clearTimeout(marker);
      }
      try {
          // when when somebody has screwed with setTimeout but no I.E. maddness
          return cachedClearTimeout(marker);
      } catch (e){
          try {
              // When we are in I.E. but the script has been evaled so I.E. doesn't  trust the global object when called normally
              return cachedClearTimeout.call(null, marker);
          } catch (e){
              // same as above but when it's a version of I.E. that must have the global object for 'this', hopfully our context correct otherwise it will throw a global error.
              // Some versions of I.E. have different rules for clearTimeout vs setTimeout
              return cachedClearTimeout.call(this, marker);
          }
      }
  
  
  
  }
  var queue = [];
  var draining = false;
  var currentQueue;
  var queueIndex = -1;
  
  function cleanUpNextTick() {
      if (!draining || !currentQueue) {
          return;
      }
      draining = false;
      if (currentQueue.length) {
          queue = currentQueue.concat(queue);
      } else {
          queueIndex = -1;
      }
      if (queue.length) {
          drainQueue();
      }
  }
  
  function drainQueue() {
      if (draining) {
          return;
      }
      var timeout = runTimeout(cleanUpNextTick);
      draining = true;
  
      var len = queue.length;
      while(len) {
          currentQueue = queue;
          queue = [];
          while (++queueIndex < len) {
              if (currentQueue) {
                  currentQueue[queueIndex].run();
              }
          }
          queueIndex = -1;
          len = queue.length;
      }
      currentQueue = null;
      draining = false;
      runClearTimeout(timeout);
  }
  
  process.nextTick = function (fun) {
      var args = new Array(arguments.length - 1);
      if (arguments.length > 1) {
          for (var i = 1; i < arguments.length; i++) {
              args[i - 1] = arguments[i];
          }
      }
      queue.push(new Item(fun, args));
      if (queue.length === 1 && !draining) {
          runTimeout(drainQueue);
      }
  };
  
  // v8 likes predictible objects
  function Item(fun, array) {
      this.fun = fun;
      this.array = array;
  }
  Item.prototype.run = function () {
      this.fun.apply(null, this.array);
  };
  process.title = 'browser';
  process.browser = true;
  process.env = {};
  process.argv = [];
  process.version = ''; // empty string to avoid regexp issues
  process.versions = {};
  
  function noop() {}
  
  process.on = noop;
  process.addListener = noop;
  process.once = noop;
  process.off = noop;
  process.removeListener = noop;
  process.removeAllListeners = noop;
  process.emit = noop;
  process.prependListener = noop;
  process.prependOnceListener = noop;
  
  process.listeners = function (name) { return [] }
  
  process.binding = function (name) {
      throw new Error('process.binding is not supported');
  };
  
  process.cwd = function () { return '/' };
  process.chdir = function (dir) {
      throw new Error('process.chdir is not supported');
  };
  process.umask = function() { return 0; };
  
  },{}],18:[function(require,module,exports){
  /*! queue-microtask. MIT License. Feross Aboukhadijeh <https://feross.org/opensource> */
  let promise
  
  module.exports = typeof queueMicrotask === 'function'
    ? queueMicrotask.bind(globalThis)
    // reuse resolved promise, and allocate it lazily
    : cb => (promise || (promise = Promise.resolve()))
      .then(cb)
      .catch(err => setTimeout(() => { throw err }, 0))
  
  },{}],19:[function(require,module,exports){
  (function (process,global){(function (){
  'use strict'
  
  // limit of Crypto.getRandomValues()
  // https://developer.mozilla.org/en-US/docs/Web/API/Crypto/getRandomValues
  var MAX_BYTES = 65536
  
  // Node supports requesting up to this number of bytes
  // https://github.com/nodejs/node/blob/master/lib/internal/crypto/random.js#L48
  var MAX_UINT32 = 4294967295
  
  function oldBrowser () {
    throw new Error('Secure random number generation is not supported by this browser.\nUse Chrome, Firefox or Internet Explorer 11')
  }
  
  var Buffer = require('safe-buffer').Buffer
  var crypto = global.crypto || global.msCrypto
  
  if (crypto && crypto.getRandomValues) {
    module.exports = randomBytes
  } else {
    module.exports = oldBrowser
  }
  
  function randomBytes (size, cb) {
    // phantomjs needs to throw
    if (size > MAX_UINT32) throw new RangeError('requested too many random bytes')
  
    var bytes = Buffer.allocUnsafe(size)
  
    if (size > 0) {  // getRandomValues fails on IE if size == 0
      if (size > MAX_BYTES) { // this is the max bytes crypto.getRandomValues
        // can do at once see https://developer.mozilla.org/en-US/docs/Web/API/window.crypto.getRandomValues
        for (var generated = 0; generated < size; generated += MAX_BYTES) {
          // buffer.slice automatically checks if the end is past the end of
          // the buffer so we don't have to here
          crypto.getRandomValues(bytes.slice(generated, generated + MAX_BYTES))
        }
      } else {
        crypto.getRandomValues(bytes)
      }
    }
  
    if (typeof cb === 'function') {
      return process.nextTick(function () {
        cb(null, bytes)
      })
    }
  
    return bytes
  }
  
  }).call(this)}).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
  
  },{"_process":17,"safe-buffer":36}],20:[function(require,module,exports){
  'use strict';
  
  function _inheritsLoose(subClass, superClass) { subClass.prototype = Object.create(superClass.prototype); subClass.prototype.constructor = subClass; subClass.__proto__ = superClass; }
  
  var codes = {};
  
  function createErrorType(code, message, Base) {
    if (!Base) {
      Base = Error;
    }
  
    function getMessage(arg1, arg2, arg3) {
      if (typeof message === 'string') {
        return message;
      } else {
        return message(arg1, arg2, arg3);
      }
    }
  
    var NodeError =
    /*#__PURE__*/
    function (_Base) {
      _inheritsLoose(NodeError, _Base);
  
      function NodeError(arg1, arg2, arg3) {
        return _Base.call(this, getMessage(arg1, arg2, arg3)) || this;
      }
  
      return NodeError;
    }(Base);
  
    NodeError.prototype.name = Base.name;
    NodeError.prototype.code = code;
    codes[code] = NodeError;
  } // https://github.com/nodejs/node/blob/v10.8.0/lib/internal/errors.js
  
  
  function oneOf(expected, thing) {
    if (Array.isArray(expected)) {
      var len = expected.length;
      expected = expected.map(function (i) {
        return String(i);
      });
  
      if (len > 2) {
        return "one of ".concat(thing, " ").concat(expected.slice(0, len - 1).join(', '), ", or ") + expected[len - 1];
      } else if (len === 2) {
        return "one of ".concat(thing, " ").concat(expected[0], " or ").concat(expected[1]);
      } else {
        return "of ".concat(thing, " ").concat(expected[0]);
      }
    } else {
      return "of ".concat(thing, " ").concat(String(expected));
    }
  } // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/startsWith
  
  
  function startsWith(str, search, pos) {
    return str.substr(!pos || pos < 0 ? 0 : +pos, search.length) === search;
  } // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/endsWith
  
  
  function endsWith(str, search, this_len) {
    if (this_len === undefined || this_len > str.length) {
      this_len = str.length;
    }
  
    return str.substring(this_len - search.length, this_len) === search;
  } // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/includes
  
  
  function includes(str, search, start) {
    if (typeof start !== 'number') {
      start = 0;
    }
  
    if (start + search.length > str.length) {
      return false;
    } else {
      return str.indexOf(search, start) !== -1;
    }
  }
  
  createErrorType('ERR_INVALID_OPT_VALUE', function (name, value) {
    return 'The value "' + value + '" is invalid for option "' + name + '"';
  }, TypeError);
  createErrorType('ERR_INVALID_ARG_TYPE', function (name, expected, actual) {
    // determiner: 'must be' or 'must not be'
    var determiner;
  
    if (typeof expected === 'string' && startsWith(expected, 'not ')) {
      determiner = 'must not be';
      expected = expected.replace(/^not /, '');
    } else {
      determiner = 'must be';
    }
  
    var msg;
  
    if (endsWith(name, ' argument')) {
      // For cases like 'first argument'
      msg = "The ".concat(name, " ").concat(determiner, " ").concat(oneOf(expected, 'type'));
    } else {
      var type = includes(name, '.') ? 'property' : 'argument';
      msg = "The \"".concat(name, "\" ").concat(type, " ").concat(determiner, " ").concat(oneOf(expected, 'type'));
    }
  
    msg += ". Received type ".concat(typeof actual);
    return msg;
  }, TypeError);
  createErrorType('ERR_STREAM_PUSH_AFTER_EOF', 'stream.push() after EOF');
  createErrorType('ERR_METHOD_NOT_IMPLEMENTED', function (name) {
    return 'The ' + name + ' method is not implemented';
  });
  createErrorType('ERR_STREAM_PREMATURE_CLOSE', 'Premature close');
  createErrorType('ERR_STREAM_DESTROYED', function (name) {
    return 'Cannot call ' + name + ' after a stream was destroyed';
  });
  createErrorType('ERR_MULTIPLE_CALLBACK', 'Callback called multiple times');
  createErrorType('ERR_STREAM_CANNOT_PIPE', 'Cannot pipe, not readable');
  createErrorType('ERR_STREAM_WRITE_AFTER_END', 'write after end');
  createErrorType('ERR_STREAM_NULL_VALUES', 'May not write null values to stream', TypeError);
  createErrorType('ERR_UNKNOWN_ENCODING', function (arg) {
    return 'Unknown encoding: ' + arg;
  }, TypeError);
  createErrorType('ERR_STREAM_UNSHIFT_AFTER_END_EVENT', 'stream.unshift() after end event');
  module.exports.codes = codes;
  
  },{}],21:[function(require,module,exports){
  (function (process){(function (){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  // a duplex stream is just a stream that is both readable and writable.
  // Since JS doesn't have multiple prototypal inheritance, this class
  // prototypally inherits from Readable, and then parasitically from
  // Writable.
  'use strict';
  /*<replacement>*/
  
  var objectKeys = Object.keys || function (obj) {
    var keys = [];
  
    for (var key in obj) {
      keys.push(key);
    }
  
    return keys;
  };
  /*</replacement>*/
  
  
  module.exports = Duplex;
  
  var Readable = require('./_stream_readable');
  
  var Writable = require('./_stream_writable');
  
  require('inherits')(Duplex, Readable);
  
  {
    // Allow the keys array to be GC'ed.
    var keys = objectKeys(Writable.prototype);
  
    for (var v = 0; v < keys.length; v++) {
      var method = keys[v];
      if (!Duplex.prototype[method]) Duplex.prototype[method] = Writable.prototype[method];
    }
  }
  
  function Duplex(options) {
    if (!(this instanceof Duplex)) return new Duplex(options);
    Readable.call(this, options);
    Writable.call(this, options);
    this.allowHalfOpen = true;
  
    if (options) {
      if (options.readable === false) this.readable = false;
      if (options.writable === false) this.writable = false;
  
      if (options.allowHalfOpen === false) {
        this.allowHalfOpen = false;
        this.once('end', onend);
      }
    }
  }
  
  Object.defineProperty(Duplex.prototype, 'writableHighWaterMark', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      return this._writableState.highWaterMark;
    }
  });
  Object.defineProperty(Duplex.prototype, 'writableBuffer', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      return this._writableState && this._writableState.getBuffer();
    }
  });
  Object.defineProperty(Duplex.prototype, 'writableLength', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      return this._writableState.length;
    }
  }); // the no-half-open enforcer
  
  function onend() {
    // If the writable side ended, then we're ok.
    if (this._writableState.ended) return; // no more data can be written.
    // But allow more writes to happen in this tick.
  
    process.nextTick(onEndNT, this);
  }
  
  function onEndNT(self) {
    self.end();
  }
  
  Object.defineProperty(Duplex.prototype, 'destroyed', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      if (this._readableState === undefined || this._writableState === undefined) {
        return false;
      }
  
      return this._readableState.destroyed && this._writableState.destroyed;
    },
    set: function set(value) {
      // we ignore the value if the stream
      // has not been initialized yet
      if (this._readableState === undefined || this._writableState === undefined) {
        return;
      } // backward compatibility, the user is explicitly
      // managing destroyed
  
  
      this._readableState.destroyed = value;
      this._writableState.destroyed = value;
    }
  });
  }).call(this)}).call(this,require('_process'))
  
  },{"./_stream_readable":23,"./_stream_writable":25,"_process":17,"inherits":14}],22:[function(require,module,exports){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  // a passthrough stream.
  // basically just the most minimal sort of Transform stream.
  // Every written chunk gets output as-is.
  'use strict';
  
  module.exports = PassThrough;
  
  var Transform = require('./_stream_transform');
  
  require('inherits')(PassThrough, Transform);
  
  function PassThrough(options) {
    if (!(this instanceof PassThrough)) return new PassThrough(options);
    Transform.call(this, options);
  }
  
  PassThrough.prototype._transform = function (chunk, encoding, cb) {
    cb(null, chunk);
  };
  },{"./_stream_transform":24,"inherits":14}],23:[function(require,module,exports){
  (function (process,global){(function (){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  'use strict';
  
  module.exports = Readable;
  /*<replacement>*/
  
  var Duplex;
  /*</replacement>*/
  
  Readable.ReadableState = ReadableState;
  /*<replacement>*/
  
  var EE = require('events').EventEmitter;
  
  var EElistenerCount = function EElistenerCount(emitter, type) {
    return emitter.listeners(type).length;
  };
  /*</replacement>*/
  
  /*<replacement>*/
  
  
  var Stream = require('./internal/streams/stream');
  /*</replacement>*/
  
  
  var Buffer = require('buffer').Buffer;
  
  var OurUint8Array = global.Uint8Array || function () {};
  
  function _uint8ArrayToBuffer(chunk) {
    return Buffer.from(chunk);
  }
  
  function _isUint8Array(obj) {
    return Buffer.isBuffer(obj) || obj instanceof OurUint8Array;
  }
  /*<replacement>*/
  
  
  var debugUtil = require('util');
  
  var debug;
  
  if (debugUtil && debugUtil.debuglog) {
    debug = debugUtil.debuglog('stream');
  } else {
    debug = function debug() {};
  }
  /*</replacement>*/
  
  
  var BufferList = require('./internal/streams/buffer_list');
  
  var destroyImpl = require('./internal/streams/destroy');
  
  var _require = require('./internal/streams/state'),
      getHighWaterMark = _require.getHighWaterMark;
  
  var _require$codes = require('../errors').codes,
      ERR_INVALID_ARG_TYPE = _require$codes.ERR_INVALID_ARG_TYPE,
      ERR_STREAM_PUSH_AFTER_EOF = _require$codes.ERR_STREAM_PUSH_AFTER_EOF,
      ERR_METHOD_NOT_IMPLEMENTED = _require$codes.ERR_METHOD_NOT_IMPLEMENTED,
      ERR_STREAM_UNSHIFT_AFTER_END_EVENT = _require$codes.ERR_STREAM_UNSHIFT_AFTER_END_EVENT; // Lazy loaded to improve the startup performance.
  
  
  var StringDecoder;
  var createReadableStreamAsyncIterator;
  var from;
  
  require('inherits')(Readable, Stream);
  
  var errorOrDestroy = destroyImpl.errorOrDestroy;
  var kProxyEvents = ['error', 'close', 'destroy', 'pause', 'resume'];
  
  function prependListener(emitter, event, fn) {
    // Sadly this is not cacheable as some libraries bundle their own
    // event emitter implementation with them.
    if (typeof emitter.prependListener === 'function') return emitter.prependListener(event, fn); // This is a hack to make sure that our error handler is attached before any
    // userland ones.  NEVER DO THIS. This is here only because this code needs
    // to continue to work with older versions of Node.js that do not include
    // the prependListener() method. The goal is to eventually remove this hack.
  
    if (!emitter._events || !emitter._events[event]) emitter.on(event, fn);else if (Array.isArray(emitter._events[event])) emitter._events[event].unshift(fn);else emitter._events[event] = [fn, emitter._events[event]];
  }
  
  function ReadableState(options, stream, isDuplex) {
    Duplex = Duplex || require('./_stream_duplex');
    options = options || {}; // Duplex streams are both readable and writable, but share
    // the same options object.
    // However, some cases require setting options to different
    // values for the readable and the writable sides of the duplex stream.
    // These options can be provided separately as readableXXX and writableXXX.
  
    if (typeof isDuplex !== 'boolean') isDuplex = stream instanceof Duplex; // object stream flag. Used to make read(n) ignore n and to
    // make all the buffer merging and length checks go away
  
    this.objectMode = !!options.objectMode;
    if (isDuplex) this.objectMode = this.objectMode || !!options.readableObjectMode; // the point at which it stops calling _read() to fill the buffer
    // Note: 0 is a valid value, means "don't call _read preemptively ever"
  
    this.highWaterMark = getHighWaterMark(this, options, 'readableHighWaterMark', isDuplex); // A linked list is used to store data chunks instead of an array because the
    // linked list can remove elements from the beginning faster than
    // array.shift()
  
    this.buffer = new BufferList();
    this.length = 0;
    this.pipes = null;
    this.pipesCount = 0;
    this.flowing = null;
    this.ended = false;
    this.endEmitted = false;
    this.reading = false; // a flag to be able to tell if the event 'readable'/'data' is emitted
    // immediately, or on a later tick.  We set this to true at first, because
    // any actions that shouldn't happen until "later" should generally also
    // not happen before the first read call.
  
    this.sync = true; // whenever we return null, then we set a flag to say
    // that we're awaiting a 'readable' event emission.
  
    this.needReadable = false;
    this.emittedReadable = false;
    this.readableListening = false;
    this.resumeScheduled = false;
    this.paused = true; // Should close be emitted on destroy. Defaults to true.
  
    this.emitClose = options.emitClose !== false; // Should .destroy() be called after 'end' (and potentially 'finish')
  
    this.autoDestroy = !!options.autoDestroy; // has it been destroyed
  
    this.destroyed = false; // Crypto is kind of old and crusty.  Historically, its default string
    // encoding is 'binary' so we have to make this configurable.
    // Everything else in the universe uses 'utf8', though.
  
    this.defaultEncoding = options.defaultEncoding || 'utf8'; // the number of writers that are awaiting a drain event in .pipe()s
  
    this.awaitDrain = 0; // if true, a maybeReadMore has been scheduled
  
    this.readingMore = false;
    this.decoder = null;
    this.encoding = null;
  
    if (options.encoding) {
      if (!StringDecoder) StringDecoder = require('string_decoder/').StringDecoder;
      this.decoder = new StringDecoder(options.encoding);
      this.encoding = options.encoding;
    }
  }
  
  function Readable(options) {
    Duplex = Duplex || require('./_stream_duplex');
    if (!(this instanceof Readable)) return new Readable(options); // Checking for a Stream.Duplex instance is faster here instead of inside
    // the ReadableState constructor, at least with V8 6.5
  
    var isDuplex = this instanceof Duplex;
    this._readableState = new ReadableState(options, this, isDuplex); // legacy
  
    this.readable = true;
  
    if (options) {
      if (typeof options.read === 'function') this._read = options.read;
      if (typeof options.destroy === 'function') this._destroy = options.destroy;
    }
  
    Stream.call(this);
  }
  
  Object.defineProperty(Readable.prototype, 'destroyed', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      if (this._readableState === undefined) {
        return false;
      }
  
      return this._readableState.destroyed;
    },
    set: function set(value) {
      // we ignore the value if the stream
      // has not been initialized yet
      if (!this._readableState) {
        return;
      } // backward compatibility, the user is explicitly
      // managing destroyed
  
  
      this._readableState.destroyed = value;
    }
  });
  Readable.prototype.destroy = destroyImpl.destroy;
  Readable.prototype._undestroy = destroyImpl.undestroy;
  
  Readable.prototype._destroy = function (err, cb) {
    cb(err);
  }; // Manually shove something into the read() buffer.
  // This returns true if the highWaterMark has not been hit yet,
  // similar to how Writable.write() returns true if you should
  // write() some more.
  
  
  Readable.prototype.push = function (chunk, encoding) {
    var state = this._readableState;
    var skipChunkCheck;
  
    if (!state.objectMode) {
      if (typeof chunk === 'string') {
        encoding = encoding || state.defaultEncoding;
  
        if (encoding !== state.encoding) {
          chunk = Buffer.from(chunk, encoding);
          encoding = '';
        }
  
        skipChunkCheck = true;
      }
    } else {
      skipChunkCheck = true;
    }
  
    return readableAddChunk(this, chunk, encoding, false, skipChunkCheck);
  }; // Unshift should *always* be something directly out of read()
  
  
  Readable.prototype.unshift = function (chunk) {
    return readableAddChunk(this, chunk, null, true, false);
  };
  
  function readableAddChunk(stream, chunk, encoding, addToFront, skipChunkCheck) {
    debug('readableAddChunk', chunk);
    var state = stream._readableState;
  
    if (chunk === null) {
      state.reading = false;
      onEofChunk(stream, state);
    } else {
      var er;
      if (!skipChunkCheck) er = chunkInvalid(state, chunk);
  
      if (er) {
        errorOrDestroy(stream, er);
      } else if (state.objectMode || chunk && chunk.length > 0) {
        if (typeof chunk !== 'string' && !state.objectMode && Object.getPrototypeOf(chunk) !== Buffer.prototype) {
          chunk = _uint8ArrayToBuffer(chunk);
        }
  
        if (addToFront) {
          if (state.endEmitted) errorOrDestroy(stream, new ERR_STREAM_UNSHIFT_AFTER_END_EVENT());else addChunk(stream, state, chunk, true);
        } else if (state.ended) {
          errorOrDestroy(stream, new ERR_STREAM_PUSH_AFTER_EOF());
        } else if (state.destroyed) {
          return false;
        } else {
          state.reading = false;
  
          if (state.decoder && !encoding) {
            chunk = state.decoder.write(chunk);
            if (state.objectMode || chunk.length !== 0) addChunk(stream, state, chunk, false);else maybeReadMore(stream, state);
          } else {
            addChunk(stream, state, chunk, false);
          }
        }
      } else if (!addToFront) {
        state.reading = false;
        maybeReadMore(stream, state);
      }
    } // We can push more data if we are below the highWaterMark.
    // Also, if we have no data yet, we can stand some more bytes.
    // This is to work around cases where hwm=0, such as the repl.
  
  
    return !state.ended && (state.length < state.highWaterMark || state.length === 0);
  }
  
  function addChunk(stream, state, chunk, addToFront) {
    if (state.flowing && state.length === 0 && !state.sync) {
      state.awaitDrain = 0;
      stream.emit('data', chunk);
    } else {
      // update the buffer info.
      state.length += state.objectMode ? 1 : chunk.length;
      if (addToFront) state.buffer.unshift(chunk);else state.buffer.push(chunk);
      if (state.needReadable) emitReadable(stream);
    }
  
    maybeReadMore(stream, state);
  }
  
  function chunkInvalid(state, chunk) {
    var er;
  
    if (!_isUint8Array(chunk) && typeof chunk !== 'string' && chunk !== undefined && !state.objectMode) {
      er = new ERR_INVALID_ARG_TYPE('chunk', ['string', 'Buffer', 'Uint8Array'], chunk);
    }
  
    return er;
  }
  
  Readable.prototype.isPaused = function () {
    return this._readableState.flowing === false;
  }; // backwards compatibility.
  
  
  Readable.prototype.setEncoding = function (enc) {
    if (!StringDecoder) StringDecoder = require('string_decoder/').StringDecoder;
    var decoder = new StringDecoder(enc);
    this._readableState.decoder = decoder; // If setEncoding(null), decoder.encoding equals utf8
  
    this._readableState.encoding = this._readableState.decoder.encoding; // Iterate over current buffer to convert already stored Buffers:
  
    var p = this._readableState.buffer.head;
    var content = '';
  
    while (p !== null) {
      content += decoder.write(p.data);
      p = p.next;
    }
  
    this._readableState.buffer.clear();
  
    if (content !== '') this._readableState.buffer.push(content);
    this._readableState.length = content.length;
    return this;
  }; // Don't raise the hwm > 1GB
  
  
  var MAX_HWM = 0x40000000;
  
  function computeNewHighWaterMark(n) {
    if (n >= MAX_HWM) {
      // TODO(ronag): Throw ERR_VALUE_OUT_OF_RANGE.
      n = MAX_HWM;
    } else {
      // Get the next highest power of 2 to prevent increasing hwm excessively in
      // tiny amounts
      n--;
      n |= n >>> 1;
      n |= n >>> 2;
      n |= n >>> 4;
      n |= n >>> 8;
      n |= n >>> 16;
      n++;
    }
  
    return n;
  } // This function is designed to be inlinable, so please take care when making
  // changes to the function body.
  
  
  function howMuchToRead(n, state) {
    if (n <= 0 || state.length === 0 && state.ended) return 0;
    if (state.objectMode) return 1;
  
    if (n !== n) {
      // Only flow one buffer at a time
      if (state.flowing && state.length) return state.buffer.head.data.length;else return state.length;
    } // If we're asking for more than the current hwm, then raise the hwm.
  
  
    if (n > state.highWaterMark) state.highWaterMark = computeNewHighWaterMark(n);
    if (n <= state.length) return n; // Don't have enough
  
    if (!state.ended) {
      state.needReadable = true;
      return 0;
    }
  
    return state.length;
  } // you can override either this method, or the async _read(n) below.
  
  
  Readable.prototype.read = function (n) {
    debug('read', n);
    n = parseInt(n, 10);
    var state = this._readableState;
    var nOrig = n;
    if (n !== 0) state.emittedReadable = false; // if we're doing read(0) to trigger a readable event, but we
    // already have a bunch of data in the buffer, then just trigger
    // the 'readable' event and move on.
  
    if (n === 0 && state.needReadable && ((state.highWaterMark !== 0 ? state.length >= state.highWaterMark : state.length > 0) || state.ended)) {
      debug('read: emitReadable', state.length, state.ended);
      if (state.length === 0 && state.ended) endReadable(this);else emitReadable(this);
      return null;
    }
  
    n = howMuchToRead(n, state); // if we've ended, and we're now clear, then finish it up.
  
    if (n === 0 && state.ended) {
      if (state.length === 0) endReadable(this);
      return null;
    } // All the actual chunk generation logic needs to be
    // *below* the call to _read.  The reason is that in certain
    // synthetic stream cases, such as passthrough streams, _read
    // may be a completely synchronous operation which may change
    // the state of the read buffer, providing enough data when
    // before there was *not* enough.
    //
    // So, the steps are:
    // 1. Figure out what the state of things will be after we do
    // a read from the buffer.
    //
    // 2. If that resulting state will trigger a _read, then call _read.
    // Note that this may be asynchronous, or synchronous.  Yes, it is
    // deeply ugly to write APIs this way, but that still doesn't mean
    // that the Readable class should behave improperly, as streams are
    // designed to be sync/async agnostic.
    // Take note if the _read call is sync or async (ie, if the read call
    // has returned yet), so that we know whether or not it's safe to emit
    // 'readable' etc.
    //
    // 3. Actually pull the requested chunks out of the buffer and return.
    // if we need a readable event, then we need to do some reading.
  
  
    var doRead = state.needReadable;
    debug('need readable', doRead); // if we currently have less than the highWaterMark, then also read some
  
    if (state.length === 0 || state.length - n < state.highWaterMark) {
      doRead = true;
      debug('length less than watermark', doRead);
    } // however, if we've ended, then there's no point, and if we're already
    // reading, then it's unnecessary.
  
  
    if (state.ended || state.reading) {
      doRead = false;
      debug('reading or ended', doRead);
    } else if (doRead) {
      debug('do read');
      state.reading = true;
      state.sync = true; // if the length is currently zero, then we *need* a readable event.
  
      if (state.length === 0) state.needReadable = true; // call internal read method
  
      this._read(state.highWaterMark);
  
      state.sync = false; // If _read pushed data synchronously, then `reading` will be false,
      // and we need to re-evaluate how much data we can return to the user.
  
      if (!state.reading) n = howMuchToRead(nOrig, state);
    }
  
    var ret;
    if (n > 0) ret = fromList(n, state);else ret = null;
  
    if (ret === null) {
      state.needReadable = state.length <= state.highWaterMark;
      n = 0;
    } else {
      state.length -= n;
      state.awaitDrain = 0;
    }
  
    if (state.length === 0) {
      // If we have nothing in the buffer, then we want to know
      // as soon as we *do* get something into the buffer.
      if (!state.ended) state.needReadable = true; // If we tried to read() past the EOF, then emit end on the next tick.
  
      if (nOrig !== n && state.ended) endReadable(this);
    }
  
    if (ret !== null) this.emit('data', ret);
    return ret;
  };
  
  function onEofChunk(stream, state) {
    debug('onEofChunk');
    if (state.ended) return;
  
    if (state.decoder) {
      var chunk = state.decoder.end();
  
      if (chunk && chunk.length) {
        state.buffer.push(chunk);
        state.length += state.objectMode ? 1 : chunk.length;
      }
    }
  
    state.ended = true;
  
    if (state.sync) {
      // if we are sync, wait until next tick to emit the data.
      // Otherwise we risk emitting data in the flow()
      // the readable code triggers during a read() call
      emitReadable(stream);
    } else {
      // emit 'readable' now to make sure it gets picked up.
      state.needReadable = false;
  
      if (!state.emittedReadable) {
        state.emittedReadable = true;
        emitReadable_(stream);
      }
    }
  } // Don't emit readable right away in sync mode, because this can trigger
  // another read() call => stack overflow.  This way, it might trigger
  // a nextTick recursion warning, but that's not so bad.
  
  
  function emitReadable(stream) {
    var state = stream._readableState;
    debug('emitReadable', state.needReadable, state.emittedReadable);
    state.needReadable = false;
  
    if (!state.emittedReadable) {
      debug('emitReadable', state.flowing);
      state.emittedReadable = true;
      process.nextTick(emitReadable_, stream);
    }
  }
  
  function emitReadable_(stream) {
    var state = stream._readableState;
    debug('emitReadable_', state.destroyed, state.length, state.ended);
  
    if (!state.destroyed && (state.length || state.ended)) {
      stream.emit('readable');
      state.emittedReadable = false;
    } // The stream needs another readable event if
    // 1. It is not flowing, as the flow mechanism will take
    //    care of it.
    // 2. It is not ended.
    // 3. It is below the highWaterMark, so we can schedule
    //    another readable later.
  
  
    state.needReadable = !state.flowing && !state.ended && state.length <= state.highWaterMark;
    flow(stream);
  } // at this point, the user has presumably seen the 'readable' event,
  // and called read() to consume some data.  that may have triggered
  // in turn another _read(n) call, in which case reading = true if
  // it's in progress.
  // However, if we're not ended, or reading, and the length < hwm,
  // then go ahead and try to read some more preemptively.
  
  
  function maybeReadMore(stream, state) {
    if (!state.readingMore) {
      state.readingMore = true;
      process.nextTick(maybeReadMore_, stream, state);
    }
  }
  
  function maybeReadMore_(stream, state) {
    // Attempt to read more data if we should.
    //
    // The conditions for reading more data are (one of):
    // - Not enough data buffered (state.length < state.highWaterMark). The loop
    //   is responsible for filling the buffer with enough data if such data
    //   is available. If highWaterMark is 0 and we are not in the flowing mode
    //   we should _not_ attempt to buffer any extra data. We'll get more data
    //   when the stream consumer calls read() instead.
    // - No data in the buffer, and the stream is in flowing mode. In this mode
    //   the loop below is responsible for ensuring read() is called. Failing to
    //   call read here would abort the flow and there's no other mechanism for
    //   continuing the flow if the stream consumer has just subscribed to the
    //   'data' event.
    //
    // In addition to the above conditions to keep reading data, the following
    // conditions prevent the data from being read:
    // - The stream has ended (state.ended).
    // - There is already a pending 'read' operation (state.reading). This is a
    //   case where the the stream has called the implementation defined _read()
    //   method, but they are processing the call asynchronously and have _not_
    //   called push() with new data. In this case we skip performing more
    //   read()s. The execution ends in this method again after the _read() ends
    //   up calling push() with more data.
    while (!state.reading && !state.ended && (state.length < state.highWaterMark || state.flowing && state.length === 0)) {
      var len = state.length;
      debug('maybeReadMore read 0');
      stream.read(0);
      if (len === state.length) // didn't get any data, stop spinning.
        break;
    }
  
    state.readingMore = false;
  } // abstract method.  to be overridden in specific implementation classes.
  // call cb(er, data) where data is <= n in length.
  // for virtual (non-string, non-buffer) streams, "length" is somewhat
  // arbitrary, and perhaps not very meaningful.
  
  
  Readable.prototype._read = function (n) {
    errorOrDestroy(this, new ERR_METHOD_NOT_IMPLEMENTED('_read()'));
  };
  
  Readable.prototype.pipe = function (dest, pipeOpts) {
    var src = this;
    var state = this._readableState;
  
    switch (state.pipesCount) {
      case 0:
        state.pipes = dest;
        break;
  
      case 1:
        state.pipes = [state.pipes, dest];
        break;
  
      default:
        state.pipes.push(dest);
        break;
    }
  
    state.pipesCount += 1;
    debug('pipe count=%d opts=%j', state.pipesCount, pipeOpts);
    var doEnd = (!pipeOpts || pipeOpts.end !== false) && dest !== process.stdout && dest !== process.stderr;
    var endFn = doEnd ? onend : unpipe;
    if (state.endEmitted) process.nextTick(endFn);else src.once('end', endFn);
    dest.on('unpipe', onunpipe);
  
    function onunpipe(readable, unpipeInfo) {
      debug('onunpipe');
  
      if (readable === src) {
        if (unpipeInfo && unpipeInfo.hasUnpiped === false) {
          unpipeInfo.hasUnpiped = true;
          cleanup();
        }
      }
    }
  
    function onend() {
      debug('onend');
      dest.end();
    } // when the dest drains, it reduces the awaitDrain counter
    // on the source.  This would be more elegant with a .once()
    // handler in flow(), but adding and removing repeatedly is
    // too slow.
  
  
    var ondrain = pipeOnDrain(src);
    dest.on('drain', ondrain);
    var cleanedUp = false;
  
    function cleanup() {
      debug('cleanup'); // cleanup event handlers once the pipe is broken
  
      dest.removeListener('close', onclose);
      dest.removeListener('finish', onfinish);
      dest.removeListener('drain', ondrain);
      dest.removeListener('error', onerror);
      dest.removeListener('unpipe', onunpipe);
      src.removeListener('end', onend);
      src.removeListener('end', unpipe);
      src.removeListener('data', ondata);
      cleanedUp = true; // if the reader is waiting for a drain event from this
      // specific writer, then it would cause it to never start
      // flowing again.
      // So, if this is awaiting a drain, then we just call it now.
      // If we don't know, then assume that we are waiting for one.
  
      if (state.awaitDrain && (!dest._writableState || dest._writableState.needDrain)) ondrain();
    }
  
    src.on('data', ondata);
  
    function ondata(chunk) {
      debug('ondata');
      var ret = dest.write(chunk);
      debug('dest.write', ret);
  
      if (ret === false) {
        // If the user unpiped during `dest.write()`, it is possible
        // to get stuck in a permanently paused state if that write
        // also returned false.
        // => Check whether `dest` is still a piping destination.
        if ((state.pipesCount === 1 && state.pipes === dest || state.pipesCount > 1 && indexOf(state.pipes, dest) !== -1) && !cleanedUp) {
          debug('false write response, pause', state.awaitDrain);
          state.awaitDrain++;
        }
  
        src.pause();
      }
    } // if the dest has an error, then stop piping into it.
    // however, don't suppress the throwing behavior for this.
  
  
    function onerror(er) {
      debug('onerror', er);
      unpipe();
      dest.removeListener('error', onerror);
      if (EElistenerCount(dest, 'error') === 0) errorOrDestroy(dest, er);
    } // Make sure our error handler is attached before userland ones.
  
  
    prependListener(dest, 'error', onerror); // Both close and finish should trigger unpipe, but only once.
  
    function onclose() {
      dest.removeListener('finish', onfinish);
      unpipe();
    }
  
    dest.once('close', onclose);
  
    function onfinish() {
      debug('onfinish');
      dest.removeListener('close', onclose);
      unpipe();
    }
  
    dest.once('finish', onfinish);
  
    function unpipe() {
      debug('unpipe');
      src.unpipe(dest);
    } // tell the dest that it's being piped to
  
  
    dest.emit('pipe', src); // start the flow if it hasn't been started already.
  
    if (!state.flowing) {
      debug('pipe resume');
      src.resume();
    }
  
    return dest;
  };
  
  function pipeOnDrain(src) {
    return function pipeOnDrainFunctionResult() {
      var state = src._readableState;
      debug('pipeOnDrain', state.awaitDrain);
      if (state.awaitDrain) state.awaitDrain--;
  
      if (state.awaitDrain === 0 && EElistenerCount(src, 'data')) {
        state.flowing = true;
        flow(src);
      }
    };
  }
  
  Readable.prototype.unpipe = function (dest) {
    var state = this._readableState;
    var unpipeInfo = {
      hasUnpiped: false
    }; // if we're not piping anywhere, then do nothing.
  
    if (state.pipesCount === 0) return this; // just one destination.  most common case.
  
    if (state.pipesCount === 1) {
      // passed in one, but it's not the right one.
      if (dest && dest !== state.pipes) return this;
      if (!dest) dest = state.pipes; // got a match.
  
      state.pipes = null;
      state.pipesCount = 0;
      state.flowing = false;
      if (dest) dest.emit('unpipe', this, unpipeInfo);
      return this;
    } // slow case. multiple pipe destinations.
  
  
    if (!dest) {
      // remove all.
      var dests = state.pipes;
      var len = state.pipesCount;
      state.pipes = null;
      state.pipesCount = 0;
      state.flowing = false;
  
      for (var i = 0; i < len; i++) {
        dests[i].emit('unpipe', this, {
          hasUnpiped: false
        });
      }
  
      return this;
    } // try to find the right one.
  
  
    var index = indexOf(state.pipes, dest);
    if (index === -1) return this;
    state.pipes.splice(index, 1);
    state.pipesCount -= 1;
    if (state.pipesCount === 1) state.pipes = state.pipes[0];
    dest.emit('unpipe', this, unpipeInfo);
    return this;
  }; // set up data events if they are asked for
  // Ensure readable listeners eventually get something
  
  
  Readable.prototype.on = function (ev, fn) {
    var res = Stream.prototype.on.call(this, ev, fn);
    var state = this._readableState;
  
    if (ev === 'data') {
      // update readableListening so that resume() may be a no-op
      // a few lines down. This is needed to support once('readable').
      state.readableListening = this.listenerCount('readable') > 0; // Try start flowing on next tick if stream isn't explicitly paused
  
      if (state.flowing !== false) this.resume();
    } else if (ev === 'readable') {
      if (!state.endEmitted && !state.readableListening) {
        state.readableListening = state.needReadable = true;
        state.flowing = false;
        state.emittedReadable = false;
        debug('on readable', state.length, state.reading);
  
        if (state.length) {
          emitReadable(this);
        } else if (!state.reading) {
          process.nextTick(nReadingNextTick, this);
        }
      }
    }
  
    return res;
  };
  
  Readable.prototype.addListener = Readable.prototype.on;
  
  Readable.prototype.removeListener = function (ev, fn) {
    var res = Stream.prototype.removeListener.call(this, ev, fn);
  
    if (ev === 'readable') {
      // We need to check if there is someone still listening to
      // readable and reset the state. However this needs to happen
      // after readable has been emitted but before I/O (nextTick) to
      // support once('readable', fn) cycles. This means that calling
      // resume within the same tick will have no
      // effect.
      process.nextTick(updateReadableListening, this);
    }
  
    return res;
  };
  
  Readable.prototype.removeAllListeners = function (ev) {
    var res = Stream.prototype.removeAllListeners.apply(this, arguments);
  
    if (ev === 'readable' || ev === undefined) {
      // We need to check if there is someone still listening to
      // readable and reset the state. However this needs to happen
      // after readable has been emitted but before I/O (nextTick) to
      // support once('readable', fn) cycles. This means that calling
      // resume within the same tick will have no
      // effect.
      process.nextTick(updateReadableListening, this);
    }
  
    return res;
  };
  
  function updateReadableListening(self) {
    var state = self._readableState;
    state.readableListening = self.listenerCount('readable') > 0;
  
    if (state.resumeScheduled && !state.paused) {
      // flowing needs to be set to true now, otherwise
      // the upcoming resume will not flow.
      state.flowing = true; // crude way to check if we should resume
    } else if (self.listenerCount('data') > 0) {
      self.resume();
    }
  }
  
  function nReadingNextTick(self) {
    debug('readable nexttick read 0');
    self.read(0);
  } // pause() and resume() are remnants of the legacy readable stream API
  // If the user uses them, then switch into old mode.
  
  
  Readable.prototype.resume = function () {
    var state = this._readableState;
  
    if (!state.flowing) {
      debug('resume'); // we flow only if there is no one listening
      // for readable, but we still have to call
      // resume()
  
      state.flowing = !state.readableListening;
      resume(this, state);
    }
  
    state.paused = false;
    return this;
  };
  
  function resume(stream, state) {
    if (!state.resumeScheduled) {
      state.resumeScheduled = true;
      process.nextTick(resume_, stream, state);
    }
  }
  
  function resume_(stream, state) {
    debug('resume', state.reading);
  
    if (!state.reading) {
      stream.read(0);
    }
  
    state.resumeScheduled = false;
    stream.emit('resume');
    flow(stream);
    if (state.flowing && !state.reading) stream.read(0);
  }
  
  Readable.prototype.pause = function () {
    debug('call pause flowing=%j', this._readableState.flowing);
  
    if (this._readableState.flowing !== false) {
      debug('pause');
      this._readableState.flowing = false;
      this.emit('pause');
    }
  
    this._readableState.paused = true;
    return this;
  };
  
  function flow(stream) {
    var state = stream._readableState;
    debug('flow', state.flowing);
  
    while (state.flowing && stream.read() !== null) {
      ;
    }
  } // wrap an old-style stream as the async data source.
  // This is *not* part of the readable stream interface.
  // It is an ugly unfortunate mess of history.
  
  
  Readable.prototype.wrap = function (stream) {
    var _this = this;
  
    var state = this._readableState;
    var paused = false;
    stream.on('end', function () {
      debug('wrapped end');
  
      if (state.decoder && !state.ended) {
        var chunk = state.decoder.end();
        if (chunk && chunk.length) _this.push(chunk);
      }
  
      _this.push(null);
    });
    stream.on('data', function (chunk) {
      debug('wrapped data');
      if (state.decoder) chunk = state.decoder.write(chunk); // don't skip over falsy values in objectMode
  
      if (state.objectMode && (chunk === null || chunk === undefined)) return;else if (!state.objectMode && (!chunk || !chunk.length)) return;
  
      var ret = _this.push(chunk);
  
      if (!ret) {
        paused = true;
        stream.pause();
      }
    }); // proxy all the other methods.
    // important when wrapping filters and duplexes.
  
    for (var i in stream) {
      if (this[i] === undefined && typeof stream[i] === 'function') {
        this[i] = function methodWrap(method) {
          return function methodWrapReturnFunction() {
            return stream[method].apply(stream, arguments);
          };
        }(i);
      }
    } // proxy certain important events.
  
  
    for (var n = 0; n < kProxyEvents.length; n++) {
      stream.on(kProxyEvents[n], this.emit.bind(this, kProxyEvents[n]));
    } // when we try to consume some more bytes, simply unpause the
    // underlying stream.
  
  
    this._read = function (n) {
      debug('wrapped _read', n);
  
      if (paused) {
        paused = false;
        stream.resume();
      }
    };
  
    return this;
  };
  
  if (typeof Symbol === 'function') {
    Readable.prototype[Symbol.asyncIterator] = function () {
      if (createReadableStreamAsyncIterator === undefined) {
        createReadableStreamAsyncIterator = require('./internal/streams/async_iterator');
      }
  
      return createReadableStreamAsyncIterator(this);
    };
  }
  
  Object.defineProperty(Readable.prototype, 'readableHighWaterMark', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      return this._readableState.highWaterMark;
    }
  });
  Object.defineProperty(Readable.prototype, 'readableBuffer', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      return this._readableState && this._readableState.buffer;
    }
  });
  Object.defineProperty(Readable.prototype, 'readableFlowing', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      return this._readableState.flowing;
    },
    set: function set(state) {
      if (this._readableState) {
        this._readableState.flowing = state;
      }
    }
  }); // exposed for testing purposes only.
  
  Readable._fromList = fromList;
  Object.defineProperty(Readable.prototype, 'readableLength', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      return this._readableState.length;
    }
  }); // Pluck off n bytes from an array of buffers.
  // Length is the combined lengths of all the buffers in the list.
  // This function is designed to be inlinable, so please take care when making
  // changes to the function body.
  
  function fromList(n, state) {
    // nothing buffered
    if (state.length === 0) return null;
    var ret;
    if (state.objectMode) ret = state.buffer.shift();else if (!n || n >= state.length) {
      // read it all, truncate the list
      if (state.decoder) ret = state.buffer.join('');else if (state.buffer.length === 1) ret = state.buffer.first();else ret = state.buffer.concat(state.length);
      state.buffer.clear();
    } else {
      // read part of list
      ret = state.buffer.consume(n, state.decoder);
    }
    return ret;
  }
  
  function endReadable(stream) {
    var state = stream._readableState;
    debug('endReadable', state.endEmitted);
  
    if (!state.endEmitted) {
      state.ended = true;
      process.nextTick(endReadableNT, state, stream);
    }
  }
  
  function endReadableNT(state, stream) {
    debug('endReadableNT', state.endEmitted, state.length); // Check that we didn't get one last unshift.
  
    if (!state.endEmitted && state.length === 0) {
      state.endEmitted = true;
      stream.readable = false;
      stream.emit('end');
  
      if (state.autoDestroy) {
        // In case of duplex streams we need a way to detect
        // if the writable side is ready for autoDestroy as well
        var wState = stream._writableState;
  
        if (!wState || wState.autoDestroy && wState.finished) {
          stream.destroy();
        }
      }
    }
  }
  
  if (typeof Symbol === 'function') {
    Readable.from = function (iterable, opts) {
      if (from === undefined) {
        from = require('./internal/streams/from');
      }
  
      return from(Readable, iterable, opts);
    };
  }
  
  function indexOf(xs, x) {
    for (var i = 0, l = xs.length; i < l; i++) {
      if (xs[i] === x) return i;
    }
  
    return -1;
  }
  }).call(this)}).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
  
  },{"../errors":20,"./_stream_duplex":21,"./internal/streams/async_iterator":26,"./internal/streams/buffer_list":27,"./internal/streams/destroy":28,"./internal/streams/from":30,"./internal/streams/state":32,"./internal/streams/stream":33,"_process":17,"buffer":7,"events":8,"inherits":14,"string_decoder/":41,"util":6}],24:[function(require,module,exports){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  // a transform stream is a readable/writable stream where you do
  // something with the data.  Sometimes it's called a "filter",
  // but that's not a great name for it, since that implies a thing where
  // some bits pass through, and others are simply ignored.  (That would
  // be a valid example of a transform, of course.)
  //
  // While the output is causally related to the input, it's not a
  // necessarily symmetric or synchronous transformation.  For example,
  // a zlib stream might take multiple plain-text writes(), and then
  // emit a single compressed chunk some time in the future.
  //
  // Here's how this works:
  //
  // The Transform stream has all the aspects of the readable and writable
  // stream classes.  When you write(chunk), that calls _write(chunk,cb)
  // internally, and returns false if there's a lot of pending writes
  // buffered up.  When you call read(), that calls _read(n) until
  // there's enough pending readable data buffered up.
  //
  // In a transform stream, the written data is placed in a buffer.  When
  // _read(n) is called, it transforms the queued up data, calling the
  // buffered _write cb's as it consumes chunks.  If consuming a single
  // written chunk would result in multiple output chunks, then the first
  // outputted bit calls the readcb, and subsequent chunks just go into
  // the read buffer, and will cause it to emit 'readable' if necessary.
  //
  // This way, back-pressure is actually determined by the reading side,
  // since _read has to be called to start processing a new chunk.  However,
  // a pathological inflate type of transform can cause excessive buffering
  // here.  For example, imagine a stream where every byte of input is
  // interpreted as an integer from 0-255, and then results in that many
  // bytes of output.  Writing the 4 bytes {ff,ff,ff,ff} would result in
  // 1kb of data being output.  In this case, you could write a very small
  // amount of input, and end up with a very large amount of output.  In
  // such a pathological inflating mechanism, there'd be no way to tell
  // the system to stop doing the transform.  A single 4MB write could
  // cause the system to run out of memory.
  //
  // However, even in such a pathological case, only a single written chunk
  // would be consumed, and then the rest would wait (un-transformed) until
  // the results of the previous transformed chunk were consumed.
  'use strict';
  
  module.exports = Transform;
  
  var _require$codes = require('../errors').codes,
      ERR_METHOD_NOT_IMPLEMENTED = _require$codes.ERR_METHOD_NOT_IMPLEMENTED,
      ERR_MULTIPLE_CALLBACK = _require$codes.ERR_MULTIPLE_CALLBACK,
      ERR_TRANSFORM_ALREADY_TRANSFORMING = _require$codes.ERR_TRANSFORM_ALREADY_TRANSFORMING,
      ERR_TRANSFORM_WITH_LENGTH_0 = _require$codes.ERR_TRANSFORM_WITH_LENGTH_0;
  
  var Duplex = require('./_stream_duplex');
  
  require('inherits')(Transform, Duplex);
  
  function afterTransform(er, data) {
    var ts = this._transformState;
    ts.transforming = false;
    var cb = ts.writecb;
  
    if (cb === null) {
      return this.emit('error', new ERR_MULTIPLE_CALLBACK());
    }
  
    ts.writechunk = null;
    ts.writecb = null;
    if (data != null) // single equals check for both `null` and `undefined`
      this.push(data);
    cb(er);
    var rs = this._readableState;
    rs.reading = false;
  
    if (rs.needReadable || rs.length < rs.highWaterMark) {
      this._read(rs.highWaterMark);
    }
  }
  
  function Transform(options) {
    if (!(this instanceof Transform)) return new Transform(options);
    Duplex.call(this, options);
    this._transformState = {
      afterTransform: afterTransform.bind(this),
      needTransform: false,
      transforming: false,
      writecb: null,
      writechunk: null,
      writeencoding: null
    }; // start out asking for a readable event once data is transformed.
  
    this._readableState.needReadable = true; // we have implemented the _read method, and done the other things
    // that Readable wants before the first _read call, so unset the
    // sync guard flag.
  
    this._readableState.sync = false;
  
    if (options) {
      if (typeof options.transform === 'function') this._transform = options.transform;
      if (typeof options.flush === 'function') this._flush = options.flush;
    } // When the writable side finishes, then flush out anything remaining.
  
  
    this.on('prefinish', prefinish);
  }
  
  function prefinish() {
    var _this = this;
  
    if (typeof this._flush === 'function' && !this._readableState.destroyed) {
      this._flush(function (er, data) {
        done(_this, er, data);
      });
    } else {
      done(this, null, null);
    }
  }
  
  Transform.prototype.push = function (chunk, encoding) {
    this._transformState.needTransform = false;
    return Duplex.prototype.push.call(this, chunk, encoding);
  }; // This is the part where you do stuff!
  // override this function in implementation classes.
  // 'chunk' is an input chunk.
  //
  // Call `push(newChunk)` to pass along transformed output
  // to the readable side.  You may call 'push' zero or more times.
  //
  // Call `cb(err)` when you are done with this chunk.  If you pass
  // an error, then that'll put the hurt on the whole operation.  If you
  // never call cb(), then you'll never get another chunk.
  
  
  Transform.prototype._transform = function (chunk, encoding, cb) {
    cb(new ERR_METHOD_NOT_IMPLEMENTED('_transform()'));
  };
  
  Transform.prototype._write = function (chunk, encoding, cb) {
    var ts = this._transformState;
    ts.writecb = cb;
    ts.writechunk = chunk;
    ts.writeencoding = encoding;
  
    if (!ts.transforming) {
      var rs = this._readableState;
      if (ts.needTransform || rs.needReadable || rs.length < rs.highWaterMark) this._read(rs.highWaterMark);
    }
  }; // Doesn't matter what the args are here.
  // _transform does all the work.
  // That we got here means that the readable side wants more data.
  
  
  Transform.prototype._read = function (n) {
    var ts = this._transformState;
  
    if (ts.writechunk !== null && !ts.transforming) {
      ts.transforming = true;
  
      this._transform(ts.writechunk, ts.writeencoding, ts.afterTransform);
    } else {
      // mark that we need a transform, so that any data that comes in
      // will get processed, now that we've asked for it.
      ts.needTransform = true;
    }
  };
  
  Transform.prototype._destroy = function (err, cb) {
    Duplex.prototype._destroy.call(this, err, function (err2) {
      cb(err2);
    });
  };
  
  function done(stream, er, data) {
    if (er) return stream.emit('error', er);
    if (data != null) // single equals check for both `null` and `undefined`
      stream.push(data); // TODO(BridgeAR): Write a test for these two error cases
    // if there's nothing in the write buffer, then that means
    // that nothing more will ever be provided
  
    if (stream._writableState.length) throw new ERR_TRANSFORM_WITH_LENGTH_0();
    if (stream._transformState.transforming) throw new ERR_TRANSFORM_ALREADY_TRANSFORMING();
    return stream.push(null);
  }
  },{"../errors":20,"./_stream_duplex":21,"inherits":14}],25:[function(require,module,exports){
  (function (process,global){(function (){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  // A bit simpler than readable streams.
  // Implement an async ._write(chunk, encoding, cb), and it'll handle all
  // the drain event emission and buffering.
  'use strict';
  
  module.exports = Writable;
  /* <replacement> */
  
  function WriteReq(chunk, encoding, cb) {
    this.chunk = chunk;
    this.encoding = encoding;
    this.callback = cb;
    this.next = null;
  } // It seems a linked list but it is not
  // there will be only 2 of these for each stream
  
  
  function CorkedRequest(state) {
    var _this = this;
  
    this.next = null;
    this.entry = null;
  
    this.finish = function () {
      onCorkedFinish(_this, state);
    };
  }
  /* </replacement> */
  
  /*<replacement>*/
  
  
  var Duplex;
  /*</replacement>*/
  
  Writable.WritableState = WritableState;
  /*<replacement>*/
  
  var internalUtil = {
    deprecate: require('util-deprecate')
  };
  /*</replacement>*/
  
  /*<replacement>*/
  
  var Stream = require('./internal/streams/stream');
  /*</replacement>*/
  
  
  var Buffer = require('buffer').Buffer;
  
  var OurUint8Array = global.Uint8Array || function () {};
  
  function _uint8ArrayToBuffer(chunk) {
    return Buffer.from(chunk);
  }
  
  function _isUint8Array(obj) {
    return Buffer.isBuffer(obj) || obj instanceof OurUint8Array;
  }
  
  var destroyImpl = require('./internal/streams/destroy');
  
  var _require = require('./internal/streams/state'),
      getHighWaterMark = _require.getHighWaterMark;
  
  var _require$codes = require('../errors').codes,
      ERR_INVALID_ARG_TYPE = _require$codes.ERR_INVALID_ARG_TYPE,
      ERR_METHOD_NOT_IMPLEMENTED = _require$codes.ERR_METHOD_NOT_IMPLEMENTED,
      ERR_MULTIPLE_CALLBACK = _require$codes.ERR_MULTIPLE_CALLBACK,
      ERR_STREAM_CANNOT_PIPE = _require$codes.ERR_STREAM_CANNOT_PIPE,
      ERR_STREAM_DESTROYED = _require$codes.ERR_STREAM_DESTROYED,
      ERR_STREAM_NULL_VALUES = _require$codes.ERR_STREAM_NULL_VALUES,
      ERR_STREAM_WRITE_AFTER_END = _require$codes.ERR_STREAM_WRITE_AFTER_END,
      ERR_UNKNOWN_ENCODING = _require$codes.ERR_UNKNOWN_ENCODING;
  
  var errorOrDestroy = destroyImpl.errorOrDestroy;
  
  require('inherits')(Writable, Stream);
  
  function nop() {}
  
  function WritableState(options, stream, isDuplex) {
    Duplex = Duplex || require('./_stream_duplex');
    options = options || {}; // Duplex streams are both readable and writable, but share
    // the same options object.
    // However, some cases require setting options to different
    // values for the readable and the writable sides of the duplex stream,
    // e.g. options.readableObjectMode vs. options.writableObjectMode, etc.
  
    if (typeof isDuplex !== 'boolean') isDuplex = stream instanceof Duplex; // object stream flag to indicate whether or not this stream
    // contains buffers or objects.
  
    this.objectMode = !!options.objectMode;
    if (isDuplex) this.objectMode = this.objectMode || !!options.writableObjectMode; // the point at which write() starts returning false
    // Note: 0 is a valid value, means that we always return false if
    // the entire buffer is not flushed immediately on write()
  
    this.highWaterMark = getHighWaterMark(this, options, 'writableHighWaterMark', isDuplex); // if _final has been called
  
    this.finalCalled = false; // drain event flag.
  
    this.needDrain = false; // at the start of calling end()
  
    this.ending = false; // when end() has been called, and returned
  
    this.ended = false; // when 'finish' is emitted
  
    this.finished = false; // has it been destroyed
  
    this.destroyed = false; // should we decode strings into buffers before passing to _write?
    // this is here so that some node-core streams can optimize string
    // handling at a lower level.
  
    var noDecode = options.decodeStrings === false;
    this.decodeStrings = !noDecode; // Crypto is kind of old and crusty.  Historically, its default string
    // encoding is 'binary' so we have to make this configurable.
    // Everything else in the universe uses 'utf8', though.
  
    this.defaultEncoding = options.defaultEncoding || 'utf8'; // not an actual buffer we keep track of, but a measurement
    // of how much we're waiting to get pushed to some underlying
    // socket or file.
  
    this.length = 0; // a flag to see when we're in the middle of a write.
  
    this.writing = false; // when true all writes will be buffered until .uncork() call
  
    this.corked = 0; // a flag to be able to tell if the onwrite cb is called immediately,
    // or on a later tick.  We set this to true at first, because any
    // actions that shouldn't happen until "later" should generally also
    // not happen before the first write call.
  
    this.sync = true; // a flag to know if we're processing previously buffered items, which
    // may call the _write() callback in the same tick, so that we don't
    // end up in an overlapped onwrite situation.
  
    this.bufferProcessing = false; // the callback that's passed to _write(chunk,cb)
  
    this.onwrite = function (er) {
      onwrite(stream, er);
    }; // the callback that the user supplies to write(chunk,encoding,cb)
  
  
    this.writecb = null; // the amount that is being written when _write is called.
  
    this.writelen = 0;
    this.bufferedRequest = null;
    this.lastBufferedRequest = null; // number of pending user-supplied write callbacks
    // this must be 0 before 'finish' can be emitted
  
    this.pendingcb = 0; // emit prefinish if the only thing we're waiting for is _write cbs
    // This is relevant for synchronous Transform streams
  
    this.prefinished = false; // True if the error was already emitted and should not be thrown again
  
    this.errorEmitted = false; // Should close be emitted on destroy. Defaults to true.
  
    this.emitClose = options.emitClose !== false; // Should .destroy() be called after 'finish' (and potentially 'end')
  
    this.autoDestroy = !!options.autoDestroy; // count buffered requests
  
    this.bufferedRequestCount = 0; // allocate the first CorkedRequest, there is always
    // one allocated and free to use, and we maintain at most two
  
    this.corkedRequestsFree = new CorkedRequest(this);
  }
  
  WritableState.prototype.getBuffer = function getBuffer() {
    var current = this.bufferedRequest;
    var out = [];
  
    while (current) {
      out.push(current);
      current = current.next;
    }
  
    return out;
  };
  
  (function () {
    try {
      Object.defineProperty(WritableState.prototype, 'buffer', {
        get: internalUtil.deprecate(function writableStateBufferGetter() {
          return this.getBuffer();
        }, '_writableState.buffer is deprecated. Use _writableState.getBuffer ' + 'instead.', 'DEP0003')
      });
    } catch (_) {}
  })(); // Test _writableState for inheritance to account for Duplex streams,
  // whose prototype chain only points to Readable.
  
  
  var realHasInstance;
  
  if (typeof Symbol === 'function' && Symbol.hasInstance && typeof Function.prototype[Symbol.hasInstance] === 'function') {
    realHasInstance = Function.prototype[Symbol.hasInstance];
    Object.defineProperty(Writable, Symbol.hasInstance, {
      value: function value(object) {
        if (realHasInstance.call(this, object)) return true;
        if (this !== Writable) return false;
        return object && object._writableState instanceof WritableState;
      }
    });
  } else {
    realHasInstance = function realHasInstance(object) {
      return object instanceof this;
    };
  }
  
  function Writable(options) {
    Duplex = Duplex || require('./_stream_duplex'); // Writable ctor is applied to Duplexes, too.
    // `realHasInstance` is necessary because using plain `instanceof`
    // would return false, as no `_writableState` property is attached.
    // Trying to use the custom `instanceof` for Writable here will also break the
    // Node.js LazyTransform implementation, which has a non-trivial getter for
    // `_writableState` that would lead to infinite recursion.
    // Checking for a Stream.Duplex instance is faster here instead of inside
    // the WritableState constructor, at least with V8 6.5
  
    var isDuplex = this instanceof Duplex;
    if (!isDuplex && !realHasInstance.call(Writable, this)) return new Writable(options);
    this._writableState = new WritableState(options, this, isDuplex); // legacy.
  
    this.writable = true;
  
    if (options) {
      if (typeof options.write === 'function') this._write = options.write;
      if (typeof options.writev === 'function') this._writev = options.writev;
      if (typeof options.destroy === 'function') this._destroy = options.destroy;
      if (typeof options.final === 'function') this._final = options.final;
    }
  
    Stream.call(this);
  } // Otherwise people can pipe Writable streams, which is just wrong.
  
  
  Writable.prototype.pipe = function () {
    errorOrDestroy(this, new ERR_STREAM_CANNOT_PIPE());
  };
  
  function writeAfterEnd(stream, cb) {
    var er = new ERR_STREAM_WRITE_AFTER_END(); // TODO: defer error events consistently everywhere, not just the cb
  
    errorOrDestroy(stream, er);
    process.nextTick(cb, er);
  } // Checks that a user-supplied chunk is valid, especially for the particular
  // mode the stream is in. Currently this means that `null` is never accepted
  // and undefined/non-string values are only allowed in object mode.
  
  
  function validChunk(stream, state, chunk, cb) {
    var er;
  
    if (chunk === null) {
      er = new ERR_STREAM_NULL_VALUES();
    } else if (typeof chunk !== 'string' && !state.objectMode) {
      er = new ERR_INVALID_ARG_TYPE('chunk', ['string', 'Buffer'], chunk);
    }
  
    if (er) {
      errorOrDestroy(stream, er);
      process.nextTick(cb, er);
      return false;
    }
  
    return true;
  }
  
  Writable.prototype.write = function (chunk, encoding, cb) {
    var state = this._writableState;
    var ret = false;
  
    var isBuf = !state.objectMode && _isUint8Array(chunk);
  
    if (isBuf && !Buffer.isBuffer(chunk)) {
      chunk = _uint8ArrayToBuffer(chunk);
    }
  
    if (typeof encoding === 'function') {
      cb = encoding;
      encoding = null;
    }
  
    if (isBuf) encoding = 'buffer';else if (!encoding) encoding = state.defaultEncoding;
    if (typeof cb !== 'function') cb = nop;
    if (state.ending) writeAfterEnd(this, cb);else if (isBuf || validChunk(this, state, chunk, cb)) {
      state.pendingcb++;
      ret = writeOrBuffer(this, state, isBuf, chunk, encoding, cb);
    }
    return ret;
  };
  
  Writable.prototype.cork = function () {
    this._writableState.corked++;
  };
  
  Writable.prototype.uncork = function () {
    var state = this._writableState;
  
    if (state.corked) {
      state.corked--;
      if (!state.writing && !state.corked && !state.bufferProcessing && state.bufferedRequest) clearBuffer(this, state);
    }
  };
  
  Writable.prototype.setDefaultEncoding = function setDefaultEncoding(encoding) {
    // node::ParseEncoding() requires lower case.
    if (typeof encoding === 'string') encoding = encoding.toLowerCase();
    if (!(['hex', 'utf8', 'utf-8', 'ascii', 'binary', 'base64', 'ucs2', 'ucs-2', 'utf16le', 'utf-16le', 'raw'].indexOf((encoding + '').toLowerCase()) > -1)) throw new ERR_UNKNOWN_ENCODING(encoding);
    this._writableState.defaultEncoding = encoding;
    return this;
  };
  
  Object.defineProperty(Writable.prototype, 'writableBuffer', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      return this._writableState && this._writableState.getBuffer();
    }
  });
  
  function decodeChunk(state, chunk, encoding) {
    if (!state.objectMode && state.decodeStrings !== false && typeof chunk === 'string') {
      chunk = Buffer.from(chunk, encoding);
    }
  
    return chunk;
  }
  
  Object.defineProperty(Writable.prototype, 'writableHighWaterMark', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      return this._writableState.highWaterMark;
    }
  }); // if we're already writing something, then just put this
  // in the queue, and wait our turn.  Otherwise, call _write
  // If we return false, then we need a drain event, so set that flag.
  
  function writeOrBuffer(stream, state, isBuf, chunk, encoding, cb) {
    if (!isBuf) {
      var newChunk = decodeChunk(state, chunk, encoding);
  
      if (chunk !== newChunk) {
        isBuf = true;
        encoding = 'buffer';
        chunk = newChunk;
      }
    }
  
    var len = state.objectMode ? 1 : chunk.length;
    state.length += len;
    var ret = state.length < state.highWaterMark; // we must ensure that previous needDrain will not be reset to false.
  
    if (!ret) state.needDrain = true;
  
    if (state.writing || state.corked) {
      var last = state.lastBufferedRequest;
      state.lastBufferedRequest = {
        chunk: chunk,
        encoding: encoding,
        isBuf: isBuf,
        callback: cb,
        next: null
      };
  
      if (last) {
        last.next = state.lastBufferedRequest;
      } else {
        state.bufferedRequest = state.lastBufferedRequest;
      }
  
      state.bufferedRequestCount += 1;
    } else {
      doWrite(stream, state, false, len, chunk, encoding, cb);
    }
  
    return ret;
  }
  
  function doWrite(stream, state, writev, len, chunk, encoding, cb) {
    state.writelen = len;
    state.writecb = cb;
    state.writing = true;
    state.sync = true;
    if (state.destroyed) state.onwrite(new ERR_STREAM_DESTROYED('write'));else if (writev) stream._writev(chunk, state.onwrite);else stream._write(chunk, encoding, state.onwrite);
    state.sync = false;
  }
  
  function onwriteError(stream, state, sync, er, cb) {
    --state.pendingcb;
  
    if (sync) {
      // defer the callback if we are being called synchronously
      // to avoid piling up things on the stack
      process.nextTick(cb, er); // this can emit finish, and it will always happen
      // after error
  
      process.nextTick(finishMaybe, stream, state);
      stream._writableState.errorEmitted = true;
      errorOrDestroy(stream, er);
    } else {
      // the caller expect this to happen before if
      // it is async
      cb(er);
      stream._writableState.errorEmitted = true;
      errorOrDestroy(stream, er); // this can emit finish, but finish must
      // always follow error
  
      finishMaybe(stream, state);
    }
  }
  
  function onwriteStateUpdate(state) {
    state.writing = false;
    state.writecb = null;
    state.length -= state.writelen;
    state.writelen = 0;
  }
  
  function onwrite(stream, er) {
    var state = stream._writableState;
    var sync = state.sync;
    var cb = state.writecb;
    if (typeof cb !== 'function') throw new ERR_MULTIPLE_CALLBACK();
    onwriteStateUpdate(state);
    if (er) onwriteError(stream, state, sync, er, cb);else {
      // Check if we're actually ready to finish, but don't emit yet
      var finished = needFinish(state) || stream.destroyed;
  
      if (!finished && !state.corked && !state.bufferProcessing && state.bufferedRequest) {
        clearBuffer(stream, state);
      }
  
      if (sync) {
        process.nextTick(afterWrite, stream, state, finished, cb);
      } else {
        afterWrite(stream, state, finished, cb);
      }
    }
  }
  
  function afterWrite(stream, state, finished, cb) {
    if (!finished) onwriteDrain(stream, state);
    state.pendingcb--;
    cb();
    finishMaybe(stream, state);
  } // Must force callback to be called on nextTick, so that we don't
  // emit 'drain' before the write() consumer gets the 'false' return
  // value, and has a chance to attach a 'drain' listener.
  
  
  function onwriteDrain(stream, state) {
    if (state.length === 0 && state.needDrain) {
      state.needDrain = false;
      stream.emit('drain');
    }
  } // if there's something in the buffer waiting, then process it
  
  
  function clearBuffer(stream, state) {
    state.bufferProcessing = true;
    var entry = state.bufferedRequest;
  
    if (stream._writev && entry && entry.next) {
      // Fast case, write everything using _writev()
      var l = state.bufferedRequestCount;
      var buffer = new Array(l);
      var holder = state.corkedRequestsFree;
      holder.entry = entry;
      var count = 0;
      var allBuffers = true;
  
      while (entry) {
        buffer[count] = entry;
        if (!entry.isBuf) allBuffers = false;
        entry = entry.next;
        count += 1;
      }
  
      buffer.allBuffers = allBuffers;
      doWrite(stream, state, true, state.length, buffer, '', holder.finish); // doWrite is almost always async, defer these to save a bit of time
      // as the hot path ends with doWrite
  
      state.pendingcb++;
      state.lastBufferedRequest = null;
  
      if (holder.next) {
        state.corkedRequestsFree = holder.next;
        holder.next = null;
      } else {
        state.corkedRequestsFree = new CorkedRequest(state);
      }
  
      state.bufferedRequestCount = 0;
    } else {
      // Slow case, write chunks one-by-one
      while (entry) {
        var chunk = entry.chunk;
        var encoding = entry.encoding;
        var cb = entry.callback;
        var len = state.objectMode ? 1 : chunk.length;
        doWrite(stream, state, false, len, chunk, encoding, cb);
        entry = entry.next;
        state.bufferedRequestCount--; // if we didn't call the onwrite immediately, then
        // it means that we need to wait until it does.
        // also, that means that the chunk and cb are currently
        // being processed, so move the buffer counter past them.
  
        if (state.writing) {
          break;
        }
      }
  
      if (entry === null) state.lastBufferedRequest = null;
    }
  
    state.bufferedRequest = entry;
    state.bufferProcessing = false;
  }
  
  Writable.prototype._write = function (chunk, encoding, cb) {
    cb(new ERR_METHOD_NOT_IMPLEMENTED('_write()'));
  };
  
  Writable.prototype._writev = null;
  
  Writable.prototype.end = function (chunk, encoding, cb) {
    var state = this._writableState;
  
    if (typeof chunk === 'function') {
      cb = chunk;
      chunk = null;
      encoding = null;
    } else if (typeof encoding === 'function') {
      cb = encoding;
      encoding = null;
    }
  
    if (chunk !== null && chunk !== undefined) this.write(chunk, encoding); // .end() fully uncorks
  
    if (state.corked) {
      state.corked = 1;
      this.uncork();
    } // ignore unnecessary end() calls.
  
  
    if (!state.ending) endWritable(this, state, cb);
    return this;
  };
  
  Object.defineProperty(Writable.prototype, 'writableLength', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      return this._writableState.length;
    }
  });
  
  function needFinish(state) {
    return state.ending && state.length === 0 && state.bufferedRequest === null && !state.finished && !state.writing;
  }
  
  function callFinal(stream, state) {
    stream._final(function (err) {
      state.pendingcb--;
  
      if (err) {
        errorOrDestroy(stream, err);
      }
  
      state.prefinished = true;
      stream.emit('prefinish');
      finishMaybe(stream, state);
    });
  }
  
  function prefinish(stream, state) {
    if (!state.prefinished && !state.finalCalled) {
      if (typeof stream._final === 'function' && !state.destroyed) {
        state.pendingcb++;
        state.finalCalled = true;
        process.nextTick(callFinal, stream, state);
      } else {
        state.prefinished = true;
        stream.emit('prefinish');
      }
    }
  }
  
  function finishMaybe(stream, state) {
    var need = needFinish(state);
  
    if (need) {
      prefinish(stream, state);
  
      if (state.pendingcb === 0) {
        state.finished = true;
        stream.emit('finish');
  
        if (state.autoDestroy) {
          // In case of duplex streams we need a way to detect
          // if the readable side is ready for autoDestroy as well
          var rState = stream._readableState;
  
          if (!rState || rState.autoDestroy && rState.endEmitted) {
            stream.destroy();
          }
        }
      }
    }
  
    return need;
  }
  
  function endWritable(stream, state, cb) {
    state.ending = true;
    finishMaybe(stream, state);
  
    if (cb) {
      if (state.finished) process.nextTick(cb);else stream.once('finish', cb);
    }
  
    state.ended = true;
    stream.writable = false;
  }
  
  function onCorkedFinish(corkReq, state, err) {
    var entry = corkReq.entry;
    corkReq.entry = null;
  
    while (entry) {
      var cb = entry.callback;
      state.pendingcb--;
      cb(err);
      entry = entry.next;
    } // reuse the free corkReq.
  
  
    state.corkedRequestsFree.next = corkReq;
  }
  
  Object.defineProperty(Writable.prototype, 'destroyed', {
    // making it explicit this property is not enumerable
    // because otherwise some prototype manipulation in
    // userland will fail
    enumerable: false,
    get: function get() {
      if (this._writableState === undefined) {
        return false;
      }
  
      return this._writableState.destroyed;
    },
    set: function set(value) {
      // we ignore the value if the stream
      // has not been initialized yet
      if (!this._writableState) {
        return;
      } // backward compatibility, the user is explicitly
      // managing destroyed
  
  
      this._writableState.destroyed = value;
    }
  });
  Writable.prototype.destroy = destroyImpl.destroy;
  Writable.prototype._undestroy = destroyImpl.undestroy;
  
  Writable.prototype._destroy = function (err, cb) {
    cb(err);
  };
  }).call(this)}).call(this,require('_process'),typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
  
  },{"../errors":20,"./_stream_duplex":21,"./internal/streams/destroy":28,"./internal/streams/state":32,"./internal/streams/stream":33,"_process":17,"buffer":7,"inherits":14,"util-deprecate":42}],26:[function(require,module,exports){
  (function (process){(function (){
  'use strict';
  
  var _Object$setPrototypeO;
  
  function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
  
  var finished = require('./end-of-stream');
  
  var kLastResolve = Symbol('lastResolve');
  var kLastReject = Symbol('lastReject');
  var kError = Symbol('error');
  var kEnded = Symbol('ended');
  var kLastPromise = Symbol('lastPromise');
  var kHandlePromise = Symbol('handlePromise');
  var kStream = Symbol('stream');
  
  function createIterResult(value, done) {
    return {
      value: value,
      done: done
    };
  }
  
  function readAndResolve(iter) {
    var resolve = iter[kLastResolve];
  
    if (resolve !== null) {
      var data = iter[kStream].read(); // we defer if data is null
      // we can be expecting either 'end' or
      // 'error'
  
      if (data !== null) {
        iter[kLastPromise] = null;
        iter[kLastResolve] = null;
        iter[kLastReject] = null;
        resolve(createIterResult(data, false));
      }
    }
  }
  
  function onReadable(iter) {
    // we wait for the next tick, because it might
    // emit an error with process.nextTick
    process.nextTick(readAndResolve, iter);
  }
  
  function wrapForNext(lastPromise, iter) {
    return function (resolve, reject) {
      lastPromise.then(function () {
        if (iter[kEnded]) {
          resolve(createIterResult(undefined, true));
          return;
        }
  
        iter[kHandlePromise](resolve, reject);
      }, reject);
    };
  }
  
  var AsyncIteratorPrototype = Object.getPrototypeOf(function () {});
  var ReadableStreamAsyncIteratorPrototype = Object.setPrototypeOf((_Object$setPrototypeO = {
    get stream() {
      return this[kStream];
    },
  
    next: function next() {
      var _this = this;
  
      // if we have detected an error in the meanwhile
      // reject straight away
      var error = this[kError];
  
      if (error !== null) {
        return Promise.reject(error);
      }
  
      if (this[kEnded]) {
        return Promise.resolve(createIterResult(undefined, true));
      }
  
      if (this[kStream].destroyed) {
        // We need to defer via nextTick because if .destroy(err) is
        // called, the error will be emitted via nextTick, and
        // we cannot guarantee that there is no error lingering around
        // waiting to be emitted.
        return new Promise(function (resolve, reject) {
          process.nextTick(function () {
            if (_this[kError]) {
              reject(_this[kError]);
            } else {
              resolve(createIterResult(undefined, true));
            }
          });
        });
      } // if we have multiple next() calls
      // we will wait for the previous Promise to finish
      // this logic is optimized to support for await loops,
      // where next() is only called once at a time
  
  
      var lastPromise = this[kLastPromise];
      var promise;
  
      if (lastPromise) {
        promise = new Promise(wrapForNext(lastPromise, this));
      } else {
        // fast path needed to support multiple this.push()
        // without triggering the next() queue
        var data = this[kStream].read();
  
        if (data !== null) {
          return Promise.resolve(createIterResult(data, false));
        }
  
        promise = new Promise(this[kHandlePromise]);
      }
  
      this[kLastPromise] = promise;
      return promise;
    }
  }, _defineProperty(_Object$setPrototypeO, Symbol.asyncIterator, function () {
    return this;
  }), _defineProperty(_Object$setPrototypeO, "return", function _return() {
    var _this2 = this;
  
    // destroy(err, cb) is a private API
    // we can guarantee we have that here, because we control the
    // Readable class this is attached to
    return new Promise(function (resolve, reject) {
      _this2[kStream].destroy(null, function (err) {
        if (err) {
          reject(err);
          return;
        }
  
        resolve(createIterResult(undefined, true));
      });
    });
  }), _Object$setPrototypeO), AsyncIteratorPrototype);
  
  var createReadableStreamAsyncIterator = function createReadableStreamAsyncIterator(stream) {
    var _Object$create;
  
    var iterator = Object.create(ReadableStreamAsyncIteratorPrototype, (_Object$create = {}, _defineProperty(_Object$create, kStream, {
      value: stream,
      writable: true
    }), _defineProperty(_Object$create, kLastResolve, {
      value: null,
      writable: true
    }), _defineProperty(_Object$create, kLastReject, {
      value: null,
      writable: true
    }), _defineProperty(_Object$create, kError, {
      value: null,
      writable: true
    }), _defineProperty(_Object$create, kEnded, {
      value: stream._readableState.endEmitted,
      writable: true
    }), _defineProperty(_Object$create, kHandlePromise, {
      value: function value(resolve, reject) {
        var data = iterator[kStream].read();
  
        if (data) {
          iterator[kLastPromise] = null;
          iterator[kLastResolve] = null;
          iterator[kLastReject] = null;
          resolve(createIterResult(data, false));
        } else {
          iterator[kLastResolve] = resolve;
          iterator[kLastReject] = reject;
        }
      },
      writable: true
    }), _Object$create));
    iterator[kLastPromise] = null;
    finished(stream, function (err) {
      if (err && err.code !== 'ERR_STREAM_PREMATURE_CLOSE') {
        var reject = iterator[kLastReject]; // reject if we are waiting for data in the Promise
        // returned by next() and store the error
  
        if (reject !== null) {
          iterator[kLastPromise] = null;
          iterator[kLastResolve] = null;
          iterator[kLastReject] = null;
          reject(err);
        }
  
        iterator[kError] = err;
        return;
      }
  
      var resolve = iterator[kLastResolve];
  
      if (resolve !== null) {
        iterator[kLastPromise] = null;
        iterator[kLastResolve] = null;
        iterator[kLastReject] = null;
        resolve(createIterResult(undefined, true));
      }
  
      iterator[kEnded] = true;
    });
    stream.on('readable', onReadable.bind(null, iterator));
    return iterator;
  };
  
  module.exports = createReadableStreamAsyncIterator;
  }).call(this)}).call(this,require('_process'))
  
  },{"./end-of-stream":29,"_process":17}],27:[function(require,module,exports){
  'use strict';
  
  function ownKeys(object, enumerableOnly) { var keys = Object.keys(object); if (Object.getOwnPropertySymbols) { var symbols = Object.getOwnPropertySymbols(object); if (enumerableOnly) symbols = symbols.filter(function (sym) { return Object.getOwnPropertyDescriptor(object, sym).enumerable; }); keys.push.apply(keys, symbols); } return keys; }
  
  function _objectSpread(target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i] != null ? arguments[i] : {}; if (i % 2) { ownKeys(Object(source), true).forEach(function (key) { _defineProperty(target, key, source[key]); }); } else if (Object.getOwnPropertyDescriptors) { Object.defineProperties(target, Object.getOwnPropertyDescriptors(source)); } else { ownKeys(Object(source)).forEach(function (key) { Object.defineProperty(target, key, Object.getOwnPropertyDescriptor(source, key)); }); } } return target; }
  
  function _defineProperty(obj, key, value) { if (key in obj) { Object.defineProperty(obj, key, { value: value, enumerable: true, configurable: true, writable: true }); } else { obj[key] = value; } return obj; }
  
  function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
  
  function _defineProperties(target, props) { for (var i = 0; i < props.length; i++) { var descriptor = props[i]; descriptor.enumerable = descriptor.enumerable || false; descriptor.configurable = true; if ("value" in descriptor) descriptor.writable = true; Object.defineProperty(target, descriptor.key, descriptor); } }
  
  function _createClass(Constructor, protoProps, staticProps) { if (protoProps) _defineProperties(Constructor.prototype, protoProps); if (staticProps) _defineProperties(Constructor, staticProps); return Constructor; }
  
  var _require = require('buffer'),
      Buffer = _require.Buffer;
  
  var _require2 = require('util'),
      inspect = _require2.inspect;
  
  var custom = inspect && inspect.custom || 'inspect';
  
  function copyBuffer(src, target, offset) {
    Buffer.prototype.copy.call(src, target, offset);
  }
  
  module.exports =
  /*#__PURE__*/
  function () {
    function BufferList() {
      _classCallCheck(this, BufferList);
  
      this.head = null;
      this.tail = null;
      this.length = 0;
    }
  
    _createClass(BufferList, [{
      key: "push",
      value: function push(v) {
        var entry = {
          data: v,
          next: null
        };
        if (this.length > 0) this.tail.next = entry;else this.head = entry;
        this.tail = entry;
        ++this.length;
      }
    }, {
      key: "unshift",
      value: function unshift(v) {
        var entry = {
          data: v,
          next: this.head
        };
        if (this.length === 0) this.tail = entry;
        this.head = entry;
        ++this.length;
      }
    }, {
      key: "shift",
      value: function shift() {
        if (this.length === 0) return;
        var ret = this.head.data;
        if (this.length === 1) this.head = this.tail = null;else this.head = this.head.next;
        --this.length;
        return ret;
      }
    }, {
      key: "clear",
      value: function clear() {
        this.head = this.tail = null;
        this.length = 0;
      }
    }, {
      key: "join",
      value: function join(s) {
        if (this.length === 0) return '';
        var p = this.head;
        var ret = '' + p.data;
  
        while (p = p.next) {
          ret += s + p.data;
        }
  
        return ret;
      }
    }, {
      key: "concat",
      value: function concat(n) {
        if (this.length === 0) return Buffer.alloc(0);
        var ret = Buffer.allocUnsafe(n >>> 0);
        var p = this.head;
        var i = 0;
  
        while (p) {
          copyBuffer(p.data, ret, i);
          i += p.data.length;
          p = p.next;
        }
  
        return ret;
      } // Consumes a specified amount of bytes or characters from the buffered data.
  
    }, {
      key: "consume",
      value: function consume(n, hasStrings) {
        var ret;
  
        if (n < this.head.data.length) {
          // `slice` is the same for buffers and strings.
          ret = this.head.data.slice(0, n);
          this.head.data = this.head.data.slice(n);
        } else if (n === this.head.data.length) {
          // First chunk is a perfect match.
          ret = this.shift();
        } else {
          // Result spans more than one buffer.
          ret = hasStrings ? this._getString(n) : this._getBuffer(n);
        }
  
        return ret;
      }
    }, {
      key: "first",
      value: function first() {
        return this.head.data;
      } // Consumes a specified amount of characters from the buffered data.
  
    }, {
      key: "_getString",
      value: function _getString(n) {
        var p = this.head;
        var c = 1;
        var ret = p.data;
        n -= ret.length;
  
        while (p = p.next) {
          var str = p.data;
          var nb = n > str.length ? str.length : n;
          if (nb === str.length) ret += str;else ret += str.slice(0, n);
          n -= nb;
  
          if (n === 0) {
            if (nb === str.length) {
              ++c;
              if (p.next) this.head = p.next;else this.head = this.tail = null;
            } else {
              this.head = p;
              p.data = str.slice(nb);
            }
  
            break;
          }
  
          ++c;
        }
  
        this.length -= c;
        return ret;
      } // Consumes a specified amount of bytes from the buffered data.
  
    }, {
      key: "_getBuffer",
      value: function _getBuffer(n) {
        var ret = Buffer.allocUnsafe(n);
        var p = this.head;
        var c = 1;
        p.data.copy(ret);
        n -= p.data.length;
  
        while (p = p.next) {
          var buf = p.data;
          var nb = n > buf.length ? buf.length : n;
          buf.copy(ret, ret.length - n, 0, nb);
          n -= nb;
  
          if (n === 0) {
            if (nb === buf.length) {
              ++c;
              if (p.next) this.head = p.next;else this.head = this.tail = null;
            } else {
              this.head = p;
              p.data = buf.slice(nb);
            }
  
            break;
          }
  
          ++c;
        }
  
        this.length -= c;
        return ret;
      } // Make sure the linked list only shows the minimal necessary information.
  
    }, {
      key: custom,
      value: function value(_, options) {
        return inspect(this, _objectSpread({}, options, {
          // Only inspect one level.
          depth: 0,
          // It should not recurse.
          customInspect: false
        }));
      }
    }]);
  
    return BufferList;
  }();
  },{"buffer":7,"util":6}],28:[function(require,module,exports){
  (function (process){(function (){
  'use strict'; // undocumented cb() API, needed for core, not for public API
  
  function destroy(err, cb) {
    var _this = this;
  
    var readableDestroyed = this._readableState && this._readableState.destroyed;
    var writableDestroyed = this._writableState && this._writableState.destroyed;
  
    if (readableDestroyed || writableDestroyed) {
      if (cb) {
        cb(err);
      } else if (err) {
        if (!this._writableState) {
          process.nextTick(emitErrorNT, this, err);
        } else if (!this._writableState.errorEmitted) {
          this._writableState.errorEmitted = true;
          process.nextTick(emitErrorNT, this, err);
        }
      }
  
      return this;
    } // we set destroyed to true before firing error callbacks in order
    // to make it re-entrance safe in case destroy() is called within callbacks
  
  
    if (this._readableState) {
      this._readableState.destroyed = true;
    } // if this is a duplex stream mark the writable part as destroyed as well
  
  
    if (this._writableState) {
      this._writableState.destroyed = true;
    }
  
    this._destroy(err || null, function (err) {
      if (!cb && err) {
        if (!_this._writableState) {
          process.nextTick(emitErrorAndCloseNT, _this, err);
        } else if (!_this._writableState.errorEmitted) {
          _this._writableState.errorEmitted = true;
          process.nextTick(emitErrorAndCloseNT, _this, err);
        } else {
          process.nextTick(emitCloseNT, _this);
        }
      } else if (cb) {
        process.nextTick(emitCloseNT, _this);
        cb(err);
      } else {
        process.nextTick(emitCloseNT, _this);
      }
    });
  
    return this;
  }
  
  function emitErrorAndCloseNT(self, err) {
    emitErrorNT(self, err);
    emitCloseNT(self);
  }
  
  function emitCloseNT(self) {
    if (self._writableState && !self._writableState.emitClose) return;
    if (self._readableState && !self._readableState.emitClose) return;
    self.emit('close');
  }
  
  function undestroy() {
    if (this._readableState) {
      this._readableState.destroyed = false;
      this._readableState.reading = false;
      this._readableState.ended = false;
      this._readableState.endEmitted = false;
    }
  
    if (this._writableState) {
      this._writableState.destroyed = false;
      this._writableState.ended = false;
      this._writableState.ending = false;
      this._writableState.finalCalled = false;
      this._writableState.prefinished = false;
      this._writableState.finished = false;
      this._writableState.errorEmitted = false;
    }
  }
  
  function emitErrorNT(self, err) {
    self.emit('error', err);
  }
  
  function errorOrDestroy(stream, err) {
    // We have tests that rely on errors being emitted
    // in the same tick, so changing this is semver major.
    // For now when you opt-in to autoDestroy we allow
    // the error to be emitted nextTick. In a future
    // semver major update we should change the default to this.
    var rState = stream._readableState;
    var wState = stream._writableState;
    if (rState && rState.autoDestroy || wState && wState.autoDestroy) stream.destroy(err);else stream.emit('error', err);
  }
  
  module.exports = {
    destroy: destroy,
    undestroy: undestroy,
    errorOrDestroy: errorOrDestroy
  };
  }).call(this)}).call(this,require('_process'))
  
  },{"_process":17}],29:[function(require,module,exports){
  // Ported from https://github.com/mafintosh/end-of-stream with
  // permission from the author, Mathias Buus (@mafintosh).
  'use strict';
  
  var ERR_STREAM_PREMATURE_CLOSE = require('../../../errors').codes.ERR_STREAM_PREMATURE_CLOSE;
  
  function once(callback) {
    var called = false;
    return function () {
      if (called) return;
      called = true;
  
      for (var _len = arguments.length, args = new Array(_len), _key = 0; _key < _len; _key++) {
        args[_key] = arguments[_key];
      }
  
      callback.apply(this, args);
    };
  }
  
  function noop() {}
  
  function isRequest(stream) {
    return stream.setHeader && typeof stream.abort === 'function';
  }
  
  function eos(stream, opts, callback) {
    if (typeof opts === 'function') return eos(stream, null, opts);
    if (!opts) opts = {};
    callback = once(callback || noop);
    var readable = opts.readable || opts.readable !== false && stream.readable;
    var writable = opts.writable || opts.writable !== false && stream.writable;
  
    var onlegacyfinish = function onlegacyfinish() {
      if (!stream.writable) onfinish();
    };
  
    var writableEnded = stream._writableState && stream._writableState.finished;
  
    var onfinish = function onfinish() {
      writable = false;
      writableEnded = true;
      if (!readable) callback.call(stream);
    };
  
    var readableEnded = stream._readableState && stream._readableState.endEmitted;
  
    var onend = function onend() {
      readable = false;
      readableEnded = true;
      if (!writable) callback.call(stream);
    };
  
    var onerror = function onerror(err) {
      callback.call(stream, err);
    };
  
    var onclose = function onclose() {
      var err;
  
      if (readable && !readableEnded) {
        if (!stream._readableState || !stream._readableState.ended) err = new ERR_STREAM_PREMATURE_CLOSE();
        return callback.call(stream, err);
      }
  
      if (writable && !writableEnded) {
        if (!stream._writableState || !stream._writableState.ended) err = new ERR_STREAM_PREMATURE_CLOSE();
        return callback.call(stream, err);
      }
    };
  
    var onrequest = function onrequest() {
      stream.req.on('finish', onfinish);
    };
  
    if (isRequest(stream)) {
      stream.on('complete', onfinish);
      stream.on('abort', onclose);
      if (stream.req) onrequest();else stream.on('request', onrequest);
    } else if (writable && !stream._writableState) {
      // legacy streams
      stream.on('end', onlegacyfinish);
      stream.on('close', onlegacyfinish);
    }
  
    stream.on('end', onend);
    stream.on('finish', onfinish);
    if (opts.error !== false) stream.on('error', onerror);
    stream.on('close', onclose);
    return function () {
      stream.removeListener('complete', onfinish);
      stream.removeListener('abort', onclose);
      stream.removeListener('request', onrequest);
      if (stream.req) stream.req.removeListener('finish', onfinish);
      stream.removeListener('end', onlegacyfinish);
      stream.removeListener('close', onlegacyfinish);
      stream.removeListener('finish', onfinish);
      stream.removeListener('end', onend);
      stream.removeListener('error', onerror);
      stream.removeListener('close', onclose);
    };
  }
  
  module.exports = eos;
  },{"../../../errors":20}],30:[function(require,module,exports){
  module.exports = function () {
    throw new Error('Readable.from is not available in the browser')
  };
  
  },{}],31:[function(require,module,exports){
  // Ported from https://github.com/mafintosh/pump with
  // permission from the author, Mathias Buus (@mafintosh).
  'use strict';
  
  var eos;
  
  function once(callback) {
    var called = false;
    return function () {
      if (called) return;
      called = true;
      callback.apply(void 0, arguments);
    };
  }
  
  var _require$codes = require('../../../errors').codes,
      ERR_MISSING_ARGS = _require$codes.ERR_MISSING_ARGS,
      ERR_STREAM_DESTROYED = _require$codes.ERR_STREAM_DESTROYED;
  
  function noop(err) {
    // Rethrow the error if it exists to avoid swallowing it
    if (err) throw err;
  }
  
  function isRequest(stream) {
    return stream.setHeader && typeof stream.abort === 'function';
  }
  
  function destroyer(stream, reading, writing, callback) {
    callback = once(callback);
    var closed = false;
    stream.on('close', function () {
      closed = true;
    });
    if (eos === undefined) eos = require('./end-of-stream');
    eos(stream, {
      readable: reading,
      writable: writing
    }, function (err) {
      if (err) return callback(err);
      closed = true;
      callback();
    });
    var destroyed = false;
    return function (err) {
      if (closed) return;
      if (destroyed) return;
      destroyed = true; // request.destroy just do .end - .abort is what we want
  
      if (isRequest(stream)) return stream.abort();
      if (typeof stream.destroy === 'function') return stream.destroy();
      callback(err || new ERR_STREAM_DESTROYED('pipe'));
    };
  }
  
  function call(fn) {
    fn();
  }
  
  function pipe(from, to) {
    return from.pipe(to);
  }
  
  function popCallback(streams) {
    if (!streams.length) return noop;
    if (typeof streams[streams.length - 1] !== 'function') return noop;
    return streams.pop();
  }
  
  function pipeline() {
    for (var _len = arguments.length, streams = new Array(_len), _key = 0; _key < _len; _key++) {
      streams[_key] = arguments[_key];
    }
  
    var callback = popCallback(streams);
    if (Array.isArray(streams[0])) streams = streams[0];
  
    if (streams.length < 2) {
      throw new ERR_MISSING_ARGS('streams');
    }
  
    var error;
    var destroys = streams.map(function (stream, i) {
      var reading = i < streams.length - 1;
      var writing = i > 0;
      return destroyer(stream, reading, writing, function (err) {
        if (!error) error = err;
        if (err) destroys.forEach(call);
        if (reading) return;
        destroys.forEach(call);
        callback(error);
      });
    });
    return streams.reduce(pipe);
  }
  
  module.exports = pipeline;
  },{"../../../errors":20,"./end-of-stream":29}],32:[function(require,module,exports){
  'use strict';
  
  var ERR_INVALID_OPT_VALUE = require('../../../errors').codes.ERR_INVALID_OPT_VALUE;
  
  function highWaterMarkFrom(options, isDuplex, duplexKey) {
    return options.highWaterMark != null ? options.highWaterMark : isDuplex ? options[duplexKey] : null;
  }
  
  function getHighWaterMark(state, options, duplexKey, isDuplex) {
    var hwm = highWaterMarkFrom(options, isDuplex, duplexKey);
  
    if (hwm != null) {
      if (!(isFinite(hwm) && Math.floor(hwm) === hwm) || hwm < 0) {
        var name = isDuplex ? duplexKey : 'highWaterMark';
        throw new ERR_INVALID_OPT_VALUE(name, hwm);
      }
  
      return Math.floor(hwm);
    } // Default value
  
  
    return state.objectMode ? 16 : 16 * 1024;
  }
  
  module.exports = {
    getHighWaterMark: getHighWaterMark
  };
  },{"../../../errors":20}],33:[function(require,module,exports){
  module.exports = require('events').EventEmitter;
  
  },{"events":8}],34:[function(require,module,exports){
  exports = module.exports = require('./lib/_stream_readable.js');
  exports.Stream = exports;
  exports.Readable = exports;
  exports.Writable = require('./lib/_stream_writable.js');
  exports.Duplex = require('./lib/_stream_duplex.js');
  exports.Transform = require('./lib/_stream_transform.js');
  exports.PassThrough = require('./lib/_stream_passthrough.js');
  exports.finished = require('./lib/internal/streams/end-of-stream.js');
  exports.pipeline = require('./lib/internal/streams/pipeline.js');
  
  },{"./lib/_stream_duplex.js":21,"./lib/_stream_passthrough.js":22,"./lib/_stream_readable.js":23,"./lib/_stream_transform.js":24,"./lib/_stream_writable.js":25,"./lib/internal/streams/end-of-stream.js":29,"./lib/internal/streams/pipeline.js":31}],35:[function(require,module,exports){
  (function webpackUniversalModuleDefinition(root, factory) {
    if(typeof exports === 'object' && typeof module === 'object')
      module.exports = factory();
    else if(typeof define === 'function' && define.amd)
      define([], factory);
    else if(typeof exports === 'object')
      exports["Rusha"] = factory();
    else
      root["Rusha"] = factory();
  })(typeof self !== 'undefined' ? self : this, function() {
  return /******/ (function(modules) { // webpackBootstrap
  /******/ 	// The module cache
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  /******/ 			return installedModules[moduleId].exports;
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  /* 0 */
  /***/ (function(module, exports, __webpack_require__) {
  
  function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
  
  /* eslint-env commonjs, browser */
  
  var RushaCore = __webpack_require__(5);
  
  var _require = __webpack_require__(1),
      toHex = _require.toHex,
      ceilHeapSize = _require.ceilHeapSize;
  
  var conv = __webpack_require__(6);
  
  // Calculate the length of buffer that the sha1 routine uses
  // including the padding.
  var padlen = function (len) {
    for (len += 9; len % 64 > 0; len += 1) {}
    return len;
  };
  
  var padZeroes = function (bin, len) {
    var h8 = new Uint8Array(bin.buffer);
    var om = len % 4,
        align = len - om;
    switch (om) {
      case 0:
        h8[align + 3] = 0;
      case 1:
        h8[align + 2] = 0;
      case 2:
        h8[align + 1] = 0;
      case 3:
        h8[align + 0] = 0;
    }
    for (var i = (len >> 2) + 1; i < bin.length; i++) {
      bin[i] = 0;
    }
  };
  
  var padData = function (bin, chunkLen, msgLen) {
    bin[chunkLen >> 2] |= 0x80 << 24 - (chunkLen % 4 << 3);
    // To support msgLen >= 2 GiB, use a float division when computing the
    // high 32-bits of the big-endian message length in bits.
    bin[((chunkLen >> 2) + 2 & ~0x0f) + 14] = msgLen / (1 << 29) | 0;
    bin[((chunkLen >> 2) + 2 & ~0x0f) + 15] = msgLen << 3;
  };
  
  var getRawDigest = function (heap, padMaxChunkLen) {
    var io = new Int32Array(heap, padMaxChunkLen + 320, 5);
    var out = new Int32Array(5);
    var arr = new DataView(out.buffer);
    arr.setInt32(0, io[0], false);
    arr.setInt32(4, io[1], false);
    arr.setInt32(8, io[2], false);
    arr.setInt32(12, io[3], false);
    arr.setInt32(16, io[4], false);
    return out;
  };
  
  var Rusha = function () {
    function Rusha(chunkSize) {
      _classCallCheck(this, Rusha);
  
      chunkSize = chunkSize || 64 * 1024;
      if (chunkSize % 64 > 0) {
        throw new Error('Chunk size must be a multiple of 128 bit');
      }
      this._offset = 0;
      this._maxChunkLen = chunkSize;
      this._padMaxChunkLen = padlen(chunkSize);
      // The size of the heap is the sum of:
      // 1. The padded input message size
      // 2. The extended space the algorithm needs (320 byte)
      // 3. The 160 bit state the algoritm uses
      this._heap = new ArrayBuffer(ceilHeapSize(this._padMaxChunkLen + 320 + 20));
      this._h32 = new Int32Array(this._heap);
      this._h8 = new Int8Array(this._heap);
      this._core = new RushaCore({ Int32Array: Int32Array }, {}, this._heap);
    }
  
    Rusha.prototype._initState = function _initState(heap, padMsgLen) {
      this._offset = 0;
      var io = new Int32Array(heap, padMsgLen + 320, 5);
      io[0] = 1732584193;
      io[1] = -271733879;
      io[2] = -1732584194;
      io[3] = 271733878;
      io[4] = -1009589776;
    };
  
    Rusha.prototype._padChunk = function _padChunk(chunkLen, msgLen) {
      var padChunkLen = padlen(chunkLen);
      var view = new Int32Array(this._heap, 0, padChunkLen >> 2);
      padZeroes(view, chunkLen);
      padData(view, chunkLen, msgLen);
      return padChunkLen;
    };
  
    Rusha.prototype._write = function _write(data, chunkOffset, chunkLen, off) {
      conv(data, this._h8, this._h32, chunkOffset, chunkLen, off || 0);
    };
  
    Rusha.prototype._coreCall = function _coreCall(data, chunkOffset, chunkLen, msgLen, finalize) {
      var padChunkLen = chunkLen;
      this._write(data, chunkOffset, chunkLen);
      if (finalize) {
        padChunkLen = this._padChunk(chunkLen, msgLen);
      }
      this._core.hash(padChunkLen, this._padMaxChunkLen);
    };
  
    Rusha.prototype.rawDigest = function rawDigest(str) {
      var msgLen = str.byteLength || str.length || str.size || 0;
      this._initState(this._heap, this._padMaxChunkLen);
      var chunkOffset = 0,
          chunkLen = this._maxChunkLen;
      for (chunkOffset = 0; msgLen > chunkOffset + chunkLen; chunkOffset += chunkLen) {
        this._coreCall(str, chunkOffset, chunkLen, msgLen, false);
      }
      this._coreCall(str, chunkOffset, msgLen - chunkOffset, msgLen, true);
      return getRawDigest(this._heap, this._padMaxChunkLen);
    };
  
    Rusha.prototype.digest = function digest(str) {
      return toHex(this.rawDigest(str).buffer);
    };
  
    Rusha.prototype.digestFromString = function digestFromString(str) {
      return this.digest(str);
    };
  
    Rusha.prototype.digestFromBuffer = function digestFromBuffer(str) {
      return this.digest(str);
    };
  
    Rusha.prototype.digestFromArrayBuffer = function digestFromArrayBuffer(str) {
      return this.digest(str);
    };
  
    Rusha.prototype.resetState = function resetState() {
      this._initState(this._heap, this._padMaxChunkLen);
      return this;
    };
  
    Rusha.prototype.append = function append(chunk) {
      var chunkOffset = 0;
      var chunkLen = chunk.byteLength || chunk.length || chunk.size || 0;
      var turnOffset = this._offset % this._maxChunkLen;
      var inputLen = void 0;
  
      this._offset += chunkLen;
      while (chunkOffset < chunkLen) {
        inputLen = Math.min(chunkLen - chunkOffset, this._maxChunkLen - turnOffset);
        this._write(chunk, chunkOffset, inputLen, turnOffset);
        turnOffset += inputLen;
        chunkOffset += inputLen;
        if (turnOffset === this._maxChunkLen) {
          this._core.hash(this._maxChunkLen, this._padMaxChunkLen);
          turnOffset = 0;
        }
      }
      return this;
    };
  
    Rusha.prototype.getState = function getState() {
      var turnOffset = this._offset % this._maxChunkLen;
      var heap = void 0;
      if (!turnOffset) {
        var io = new Int32Array(this._heap, this._padMaxChunkLen + 320, 5);
        heap = io.buffer.slice(io.byteOffset, io.byteOffset + io.byteLength);
      } else {
        heap = this._heap.slice(0);
      }
      return {
        offset: this._offset,
        heap: heap
      };
    };
  
    Rusha.prototype.setState = function setState(state) {
      this._offset = state.offset;
      if (state.heap.byteLength === 20) {
        var io = new Int32Array(this._heap, this._padMaxChunkLen + 320, 5);
        io.set(new Int32Array(state.heap));
      } else {
        this._h32.set(new Int32Array(state.heap));
      }
      return this;
    };
  
    Rusha.prototype.rawEnd = function rawEnd() {
      var msgLen = this._offset;
      var chunkLen = msgLen % this._maxChunkLen;
      var padChunkLen = this._padChunk(chunkLen, msgLen);
      this._core.hash(padChunkLen, this._padMaxChunkLen);
      var result = getRawDigest(this._heap, this._padMaxChunkLen);
      this._initState(this._heap, this._padMaxChunkLen);
      return result;
    };
  
    Rusha.prototype.end = function end() {
      return toHex(this.rawEnd().buffer);
    };
  
    return Rusha;
  }();
  
  module.exports = Rusha;
  module.exports._core = RushaCore;
  
  /***/ }),
  /* 1 */
  /***/ (function(module, exports) {
  
  /* eslint-env commonjs, browser */
  
  //
  // toHex
  //
  
  var precomputedHex = new Array(256);
  for (var i = 0; i < 256; i++) {
    precomputedHex[i] = (i < 0x10 ? '0' : '') + i.toString(16);
  }
  
  module.exports.toHex = function (arrayBuffer) {
    var binarray = new Uint8Array(arrayBuffer);
    var res = new Array(arrayBuffer.byteLength);
    for (var _i = 0; _i < res.length; _i++) {
      res[_i] = precomputedHex[binarray[_i]];
    }
    return res.join('');
  };
  
  //
  // ceilHeapSize
  //
  
  module.exports.ceilHeapSize = function (v) {
    // The asm.js spec says:
    // The heap object's byteLength must be either
    // 2^n for n in [12, 24) or 2^24 * n for n ≥ 1.
    // Also, byteLengths smaller than 2^16 are deprecated.
    var p = 0;
    // If v is smaller than 2^16, the smallest possible solution
    // is 2^16.
    if (v <= 65536) return 65536;
    // If v < 2^24, we round up to 2^n,
    // otherwise we round up to 2^24 * n.
    if (v < 16777216) {
      for (p = 1; p < v; p = p << 1) {}
    } else {
      for (p = 16777216; p < v; p += 16777216) {}
    }
    return p;
  };
  
  //
  // isDedicatedWorkerScope
  //
  
  module.exports.isDedicatedWorkerScope = function (self) {
    var isRunningInWorker = 'WorkerGlobalScope' in self && self instanceof self.WorkerGlobalScope;
    var isRunningInSharedWorker = 'SharedWorkerGlobalScope' in self && self instanceof self.SharedWorkerGlobalScope;
    var isRunningInServiceWorker = 'ServiceWorkerGlobalScope' in self && self instanceof self.ServiceWorkerGlobalScope;
  
    // Detects whether we run inside a dedicated worker or not.
    //
    // We can't just check for `DedicatedWorkerGlobalScope`, since IE11
    // has a bug where it only supports `WorkerGlobalScope`.
    //
    // Therefore, we consider us as running inside a dedicated worker
    // when we are running inside a worker, but not in a shared or service worker.
    //
    // When new types of workers are introduced, we will need to adjust this code.
    return isRunningInWorker && !isRunningInSharedWorker && !isRunningInServiceWorker;
  };
  
  /***/ }),
  /* 2 */
  /***/ (function(module, exports, __webpack_require__) {
  
  /* eslint-env commonjs, worker */
  
  module.exports = function () {
    var Rusha = __webpack_require__(0);
  
    var hashData = function (hasher, data, cb) {
      try {
        return cb(null, hasher.digest(data));
      } catch (e) {
        return cb(e);
      }
    };
  
    var hashFile = function (hasher, readTotal, blockSize, file, cb) {
      var reader = new self.FileReader();
      reader.onloadend = function onloadend() {
        if (reader.error) {
          return cb(reader.error);
        }
        var buffer = reader.result;
        readTotal += reader.result.byteLength;
        try {
          hasher.append(buffer);
        } catch (e) {
          cb(e);
          return;
        }
        if (readTotal < file.size) {
          hashFile(hasher, readTotal, blockSize, file, cb);
        } else {
          cb(null, hasher.end());
        }
      };
      reader.readAsArrayBuffer(file.slice(readTotal, readTotal + blockSize));
    };
  
    var workerBehaviourEnabled = true;
  
    self.onmessage = function (event) {
      if (!workerBehaviourEnabled) {
        return;
      }
  
      var data = event.data.data,
          file = event.data.file,
          id = event.data.id;
      if (typeof id === 'undefined') return;
      if (!file && !data) return;
      var blockSize = event.data.blockSize || 4 * 1024 * 1024;
      var hasher = new Rusha(blockSize);
      hasher.resetState();
      var done = function (err, hash) {
        if (!err) {
          self.postMessage({ id: id, hash: hash });
        } else {
          self.postMessage({ id: id, error: err.name });
        }
      };
      if (data) hashData(hasher, data, done);
      if (file) hashFile(hasher, 0, blockSize, file, done);
    };
  
    return function () {
      workerBehaviourEnabled = false;
    };
  };
  
  /***/ }),
  /* 3 */
  /***/ (function(module, exports, __webpack_require__) {
  
  /* eslint-env commonjs, browser */
  
  var work = __webpack_require__(4);
  var Rusha = __webpack_require__(0);
  var createHash = __webpack_require__(7);
  var runWorker = __webpack_require__(2);
  
  var _require = __webpack_require__(1),
      isDedicatedWorkerScope = _require.isDedicatedWorkerScope;
  
  var isRunningInDedicatedWorker = typeof self !== 'undefined' && isDedicatedWorkerScope(self);
  
  Rusha.disableWorkerBehaviour = isRunningInDedicatedWorker ? runWorker() : function () {};
  
  Rusha.createWorker = function () {
    var worker = work(/*require.resolve*/(2));
    var terminate = worker.terminate;
    worker.terminate = function () {
      URL.revokeObjectURL(worker.objectURL);
      terminate.call(worker);
    };
    return worker;
  };
  
  Rusha.createHash = createHash;
  
  module.exports = Rusha;
  
  /***/ }),
  /* 4 */
  /***/ (function(module, exports, __webpack_require__) {
  
  function webpackBootstrapFunc (modules) {
  /******/  // The module cache
  /******/  var installedModules = {};
  
  /******/  // The require function
  /******/  function __webpack_require__(moduleId) {
  
  /******/    // Check if module is in cache
  /******/    if(installedModules[moduleId])
  /******/      return installedModules[moduleId].exports;
  
  /******/    // Create a new module (and put it into the cache)
  /******/    var module = installedModules[moduleId] = {
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  /******/      l: false,
  /******/      exports: {}
  /******/    };
  
  /******/    // Execute the module function
  /******/    modules[moduleId].call(module.exports, module, module.exports, __webpack_require__);
  
  /******/    // Flag the module as loaded
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  /******/  // expose the modules object (__webpack_modules__)
  /******/  __webpack_require__.m = modules;
  
  /******/  // expose the module cache
  /******/  __webpack_require__.c = installedModules;
  
  /******/  // identity function for calling harmony imports with the correct context
  /******/  __webpack_require__.i = function(value) { return value; };
  
  /******/  // define getter function for harmony exports
  /******/  __webpack_require__.d = function(exports, name, getter) {
  /******/    if(!__webpack_require__.o(exports, name)) {
  /******/      Object.defineProperty(exports, name, {
  /******/        configurable: false,
  /******/        enumerable: true,
  /******/        get: getter
  /******/      });
  /******/    }
  /******/  };
  
  /******/  // define __esModule on exports
  /******/  __webpack_require__.r = function(exports) {
  /******/    Object.defineProperty(exports, '__esModule', { value: true });
  /******/  };
  
  /******/  // getDefaultExport function for compatibility with non-harmony modules
  /******/  __webpack_require__.n = function(module) {
  /******/    var getter = module && module.__esModule ?
  /******/      function getDefault() { return module['default']; } :
  /******/      function getModuleExports() { return module; };
  /******/    __webpack_require__.d(getter, 'a', getter);
  /******/    return getter;
  /******/  };
  
  /******/  // Object.prototype.hasOwnProperty.call
  /******/  __webpack_require__.o = function(object, property) { return Object.prototype.hasOwnProperty.call(object, property); };
  
  /******/  // __webpack_public_path__
  /******/  __webpack_require__.p = "/";
  
  /******/  // on error function for async loading
  /******/  __webpack_require__.oe = function(err) { console.error(err); throw err; };
  
    var f = __webpack_require__(__webpack_require__.s = ENTRY_MODULE)
    return f.default || f // try to call default if defined to also support babel esmodule exports
  }
  
  var moduleNameReqExp = '[\\.|\\-|\\+|\\w|\/|@]+'
  var dependencyRegExp = '\\((\/\\*.*?\\*\/)?\s?.*?(' + moduleNameReqExp + ').*?\\)' // additional chars when output.pathinfo is true
  
  // http://stackoverflow.com/a/2593661/130442
  function quoteRegExp (str) {
    return (str + '').replace(/[.?*+^$[\]\\(){}|-]/g, '\\$&')
  }
  
  function getModuleDependencies (sources, module, queueName) {
    var retval = {}
    retval[queueName] = []
  
    var fnString = module.toString()
    var wrapperSignature = fnString.match(/^function\s?\(\w+,\s*\w+,\s*(\w+)\)/)
    if (!wrapperSignature) return retval
    var webpackRequireName = wrapperSignature[1]
  
    // main bundle deps
    var re = new RegExp('(\\\\n|\\W)' + quoteRegExp(webpackRequireName) + dependencyRegExp, 'g')
    var match
    while ((match = re.exec(fnString))) {
      if (match[3] === 'dll-reference') continue
      retval[queueName].push(match[3])
    }
  
    // dll deps
    re = new RegExp('\\(' + quoteRegExp(webpackRequireName) + '\\("(dll-reference\\s(' + moduleNameReqExp + '))"\\)\\)' + dependencyRegExp, 'g')
    while ((match = re.exec(fnString))) {
      if (!sources[match[2]]) {
        retval[queueName].push(match[1])
        sources[match[2]] = __webpack_require__(match[1]).m
      }
      retval[match[2]] = retval[match[2]] || []
      retval[match[2]].push(match[4])
    }
  
    return retval
  }
  
  function hasValuesInQueues (queues) {
    var keys = Object.keys(queues)
    return keys.reduce(function (hasValues, key) {
      return hasValues || queues[key].length > 0
    }, false)
  }
  
  function getRequiredModules (sources, moduleId) {
    var modulesQueue = {
      main: [moduleId]
    }
    var requiredModules = {
      main: []
    }
    var seenModules = {
      main: {}
    }
  
    while (hasValuesInQueues(modulesQueue)) {
      var queues = Object.keys(modulesQueue)
      for (var i = 0; i < queues.length; i++) {
        var queueName = queues[i]
        var queue = modulesQueue[queueName]
        var moduleToCheck = queue.pop()
        seenModules[queueName] = seenModules[queueName] || {}
        if (seenModules[queueName][moduleToCheck] || !sources[queueName][moduleToCheck]) continue
        seenModules[queueName][moduleToCheck] = true
        requiredModules[queueName] = requiredModules[queueName] || []
        requiredModules[queueName].push(moduleToCheck)
        var newModules = getModuleDependencies(sources, sources[queueName][moduleToCheck], queueName)
        var newModulesKeys = Object.keys(newModules)
        for (var j = 0; j < newModulesKeys.length; j++) {
          modulesQueue[newModulesKeys[j]] = modulesQueue[newModulesKeys[j]] || []
          modulesQueue[newModulesKeys[j]] = modulesQueue[newModulesKeys[j]].concat(newModules[newModulesKeys[j]])
        }
      }
    }
  
    return requiredModules
  }
  
  module.exports = function (moduleId, options) {
    options = options || {}
    var sources = {
      main: __webpack_require__.m
    }
  
    var requiredModules = options.all ? { main: Object.keys(sources) } : getRequiredModules(sources, moduleId)
  
    var src = ''
  
    Object.keys(requiredModules).filter(function (m) { return m !== 'main' }).forEach(function (module) {
      var entryModule = 0
      while (requiredModules[module][entryModule]) {
        entryModule++
      }
      requiredModules[module].push(entryModule)
      sources[module][entryModule] = '(function(module, exports, __webpack_require__) { module.exports = __webpack_require__; })'
      src = src + 'var ' + module + ' = (' + webpackBootstrapFunc.toString().replace('ENTRY_MODULE', JSON.stringify(entryModule)) + ')({' + requiredModules[module].map(function (id) { return '' + JSON.stringify(id) + ': ' + sources[module][id].toString() }).join(',') + '});\n'
    })
  
    src = src + '(' + webpackBootstrapFunc.toString().replace('ENTRY_MODULE', JSON.stringify(moduleId)) + ')({' + requiredModules.main.map(function (id) { return '' + JSON.stringify(id) + ': ' + sources.main[id].toString() }).join(',') + '})(self);'
  
    var blob = new window.Blob([src], { type: 'text/javascript' })
    if (options.bare) { return blob }
  
    var URL = window.URL || window.webkitURL || window.mozURL || window.msURL
  
    var workerUrl = URL.createObjectURL(blob)
    var worker = new window.Worker(workerUrl)
    worker.objectURL = workerUrl
  
    return worker
  }
  
  
  /***/ }),
  /* 5 */
  /***/ (function(module, exports) {
  
  // The low-level RushCore module provides the heart of Rusha,
  // a high-speed sha1 implementation working on an Int32Array heap.
  // At first glance, the implementation seems complicated, however
  // with the SHA1 spec at hand, it is obvious this almost a textbook
  // implementation that has a few functions hand-inlined and a few loops
  // hand-unrolled.
  module.exports = function RushaCore(stdlib$846, foreign$847, heap$848) {
      'use asm';
      var H$849 = new stdlib$846.Int32Array(heap$848);
      function hash$850(k$851, x$852) {
          // k in bytes
          k$851 = k$851 | 0;
          x$852 = x$852 | 0;
          var i$853 = 0, j$854 = 0, y0$855 = 0, z0$856 = 0, y1$857 = 0, z1$858 = 0, y2$859 = 0, z2$860 = 0, y3$861 = 0, z3$862 = 0, y4$863 = 0, z4$864 = 0, t0$865 = 0, t1$866 = 0;
          y0$855 = H$849[x$852 + 320 >> 2] | 0;
          y1$857 = H$849[x$852 + 324 >> 2] | 0;
          y2$859 = H$849[x$852 + 328 >> 2] | 0;
          y3$861 = H$849[x$852 + 332 >> 2] | 0;
          y4$863 = H$849[x$852 + 336 >> 2] | 0;
          for (i$853 = 0; (i$853 | 0) < (k$851 | 0); i$853 = i$853 + 64 | 0) {
              z0$856 = y0$855;
              z1$858 = y1$857;
              z2$860 = y2$859;
              z3$862 = y3$861;
              z4$864 = y4$863;
              for (j$854 = 0; (j$854 | 0) < 64; j$854 = j$854 + 4 | 0) {
                  t1$866 = H$849[i$853 + j$854 >> 2] | 0;
                  t0$865 = ((y0$855 << 5 | y0$855 >>> 27) + (y1$857 & y2$859 | ~y1$857 & y3$861) | 0) + ((t1$866 + y4$863 | 0) + 1518500249 | 0) | 0;
                  y4$863 = y3$861;
                  y3$861 = y2$859;
                  y2$859 = y1$857 << 30 | y1$857 >>> 2;
                  y1$857 = y0$855;
                  y0$855 = t0$865;
                  H$849[k$851 + j$854 >> 2] = t1$866;
              }
              for (j$854 = k$851 + 64 | 0; (j$854 | 0) < (k$851 + 80 | 0); j$854 = j$854 + 4 | 0) {
                  t1$866 = (H$849[j$854 - 12 >> 2] ^ H$849[j$854 - 32 >> 2] ^ H$849[j$854 - 56 >> 2] ^ H$849[j$854 - 64 >> 2]) << 1 | (H$849[j$854 - 12 >> 2] ^ H$849[j$854 - 32 >> 2] ^ H$849[j$854 - 56 >> 2] ^ H$849[j$854 - 64 >> 2]) >>> 31;
                  t0$865 = ((y0$855 << 5 | y0$855 >>> 27) + (y1$857 & y2$859 | ~y1$857 & y3$861) | 0) + ((t1$866 + y4$863 | 0) + 1518500249 | 0) | 0;
                  y4$863 = y3$861;
                  y3$861 = y2$859;
                  y2$859 = y1$857 << 30 | y1$857 >>> 2;
                  y1$857 = y0$855;
                  y0$855 = t0$865;
                  H$849[j$854 >> 2] = t1$866;
              }
              for (j$854 = k$851 + 80 | 0; (j$854 | 0) < (k$851 + 160 | 0); j$854 = j$854 + 4 | 0) {
                  t1$866 = (H$849[j$854 - 12 >> 2] ^ H$849[j$854 - 32 >> 2] ^ H$849[j$854 - 56 >> 2] ^ H$849[j$854 - 64 >> 2]) << 1 | (H$849[j$854 - 12 >> 2] ^ H$849[j$854 - 32 >> 2] ^ H$849[j$854 - 56 >> 2] ^ H$849[j$854 - 64 >> 2]) >>> 31;
                  t0$865 = ((y0$855 << 5 | y0$855 >>> 27) + (y1$857 ^ y2$859 ^ y3$861) | 0) + ((t1$866 + y4$863 | 0) + 1859775393 | 0) | 0;
                  y4$863 = y3$861;
                  y3$861 = y2$859;
                  y2$859 = y1$857 << 30 | y1$857 >>> 2;
                  y1$857 = y0$855;
                  y0$855 = t0$865;
                  H$849[j$854 >> 2] = t1$866;
              }
              for (j$854 = k$851 + 160 | 0; (j$854 | 0) < (k$851 + 240 | 0); j$854 = j$854 + 4 | 0) {
                  t1$866 = (H$849[j$854 - 12 >> 2] ^ H$849[j$854 - 32 >> 2] ^ H$849[j$854 - 56 >> 2] ^ H$849[j$854 - 64 >> 2]) << 1 | (H$849[j$854 - 12 >> 2] ^ H$849[j$854 - 32 >> 2] ^ H$849[j$854 - 56 >> 2] ^ H$849[j$854 - 64 >> 2]) >>> 31;
                  t0$865 = ((y0$855 << 5 | y0$855 >>> 27) + (y1$857 & y2$859 | y1$857 & y3$861 | y2$859 & y3$861) | 0) + ((t1$866 + y4$863 | 0) - 1894007588 | 0) | 0;
                  y4$863 = y3$861;
                  y3$861 = y2$859;
                  y2$859 = y1$857 << 30 | y1$857 >>> 2;
                  y1$857 = y0$855;
                  y0$855 = t0$865;
                  H$849[j$854 >> 2] = t1$866;
              }
              for (j$854 = k$851 + 240 | 0; (j$854 | 0) < (k$851 + 320 | 0); j$854 = j$854 + 4 | 0) {
                  t1$866 = (H$849[j$854 - 12 >> 2] ^ H$849[j$854 - 32 >> 2] ^ H$849[j$854 - 56 >> 2] ^ H$849[j$854 - 64 >> 2]) << 1 | (H$849[j$854 - 12 >> 2] ^ H$849[j$854 - 32 >> 2] ^ H$849[j$854 - 56 >> 2] ^ H$849[j$854 - 64 >> 2]) >>> 31;
                  t0$865 = ((y0$855 << 5 | y0$855 >>> 27) + (y1$857 ^ y2$859 ^ y3$861) | 0) + ((t1$866 + y4$863 | 0) - 899497514 | 0) | 0;
                  y4$863 = y3$861;
                  y3$861 = y2$859;
                  y2$859 = y1$857 << 30 | y1$857 >>> 2;
                  y1$857 = y0$855;
                  y0$855 = t0$865;
                  H$849[j$854 >> 2] = t1$866;
              }
              y0$855 = y0$855 + z0$856 | 0;
              y1$857 = y1$857 + z1$858 | 0;
              y2$859 = y2$859 + z2$860 | 0;
              y3$861 = y3$861 + z3$862 | 0;
              y4$863 = y4$863 + z4$864 | 0;
          }
          H$849[x$852 + 320 >> 2] = y0$855;
          H$849[x$852 + 324 >> 2] = y1$857;
          H$849[x$852 + 328 >> 2] = y2$859;
          H$849[x$852 + 332 >> 2] = y3$861;
          H$849[x$852 + 336 >> 2] = y4$863;
      }
      return { hash: hash$850 };
  };
  
  /***/ }),
  /* 6 */
  /***/ (function(module, exports) {
  
  var _this = this;
  
  /* eslint-env commonjs, browser */
  
  var reader = void 0;
  if (typeof self !== 'undefined' && typeof self.FileReaderSync !== 'undefined') {
    reader = new self.FileReaderSync();
  }
  
  // Convert a binary string and write it to the heap.
  // A binary string is expected to only contain char codes < 256.
  var convStr = function (str, H8, H32, start, len, off) {
    var i = void 0,
        om = off % 4,
        lm = (len + om) % 4,
        j = len - lm;
    switch (om) {
      case 0:
        H8[off] = str.charCodeAt(start + 3);
      case 1:
        H8[off + 1 - (om << 1) | 0] = str.charCodeAt(start + 2);
      case 2:
        H8[off + 2 - (om << 1) | 0] = str.charCodeAt(start + 1);
      case 3:
        H8[off + 3 - (om << 1) | 0] = str.charCodeAt(start);
    }
    if (len < lm + (4 - om)) {
      return;
    }
    for (i = 4 - om; i < j; i = i + 4 | 0) {
      H32[off + i >> 2] = str.charCodeAt(start + i) << 24 | str.charCodeAt(start + i + 1) << 16 | str.charCodeAt(start + i + 2) << 8 | str.charCodeAt(start + i + 3);
    }
    switch (lm) {
      case 3:
        H8[off + j + 1 | 0] = str.charCodeAt(start + j + 2);
      case 2:
        H8[off + j + 2 | 0] = str.charCodeAt(start + j + 1);
      case 1:
        H8[off + j + 3 | 0] = str.charCodeAt(start + j);
    }
  };
  
  // Convert a buffer or array and write it to the heap.
  // The buffer or array is expected to only contain elements < 256.
  var convBuf = function (buf, H8, H32, start, len, off) {
    var i = void 0,
        om = off % 4,
        lm = (len + om) % 4,
        j = len - lm;
    switch (om) {
      case 0:
        H8[off] = buf[start + 3];
      case 1:
        H8[off + 1 - (om << 1) | 0] = buf[start + 2];
      case 2:
        H8[off + 2 - (om << 1) | 0] = buf[start + 1];
      case 3:
        H8[off + 3 - (om << 1) | 0] = buf[start];
    }
    if (len < lm + (4 - om)) {
      return;
    }
    for (i = 4 - om; i < j; i = i + 4 | 0) {
      H32[off + i >> 2 | 0] = buf[start + i] << 24 | buf[start + i + 1] << 16 | buf[start + i + 2] << 8 | buf[start + i + 3];
    }
    switch (lm) {
      case 3:
        H8[off + j + 1 | 0] = buf[start + j + 2];
      case 2:
        H8[off + j + 2 | 0] = buf[start + j + 1];
      case 1:
        H8[off + j + 3 | 0] = buf[start + j];
    }
  };
  
  var convBlob = function (blob, H8, H32, start, len, off) {
    var i = void 0,
        om = off % 4,
        lm = (len + om) % 4,
        j = len - lm;
    var buf = new Uint8Array(reader.readAsArrayBuffer(blob.slice(start, start + len)));
    switch (om) {
      case 0:
        H8[off] = buf[3];
      case 1:
        H8[off + 1 - (om << 1) | 0] = buf[2];
      case 2:
        H8[off + 2 - (om << 1) | 0] = buf[1];
      case 3:
        H8[off + 3 - (om << 1) | 0] = buf[0];
    }
    if (len < lm + (4 - om)) {
      return;
    }
    for (i = 4 - om; i < j; i = i + 4 | 0) {
      H32[off + i >> 2 | 0] = buf[i] << 24 | buf[i + 1] << 16 | buf[i + 2] << 8 | buf[i + 3];
    }
    switch (lm) {
      case 3:
        H8[off + j + 1 | 0] = buf[j + 2];
      case 2:
        H8[off + j + 2 | 0] = buf[j + 1];
      case 1:
        H8[off + j + 3 | 0] = buf[j];
    }
  };
  
  module.exports = function (data, H8, H32, start, len, off) {
    if (typeof data === 'string') {
      return convStr(data, H8, H32, start, len, off);
    }
    if (data instanceof Array) {
      return convBuf(data, H8, H32, start, len, off);
    }
    // Safely doing a Buffer check using "this" to avoid Buffer polyfill to be included in the dist
    if (_this && _this.Buffer && _this.Buffer.isBuffer(data)) {
      return convBuf(data, H8, H32, start, len, off);
    }
    if (data instanceof ArrayBuffer) {
      return convBuf(new Uint8Array(data), H8, H32, start, len, off);
    }
    if (data.buffer instanceof ArrayBuffer) {
      return convBuf(new Uint8Array(data.buffer, data.byteOffset, data.byteLength), H8, H32, start, len, off);
    }
    if (data instanceof Blob) {
      return convBlob(data, H8, H32, start, len, off);
    }
    throw new Error('Unsupported data type.');
  };
  
  /***/ }),
  /* 7 */
  /***/ (function(module, exports, __webpack_require__) {
  
  function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }
  
  /* eslint-env commonjs, browser */
  
  var Rusha = __webpack_require__(0);
  
  var _require = __webpack_require__(1),
      toHex = _require.toHex;
  
  var Hash = function () {
    function Hash() {
      _classCallCheck(this, Hash);
  
      this._rusha = new Rusha();
      this._rusha.resetState();
    }
  
    Hash.prototype.update = function update(data) {
      this._rusha.append(data);
      return this;
    };
  
    Hash.prototype.digest = function digest(encoding) {
      var digest = this._rusha.rawEnd().buffer;
      if (!encoding) {
        return digest;
      }
      if (encoding === 'hex') {
        return toHex(digest);
      }
      throw new Error('unsupported digest encoding');
    };
  
    return Hash;
  }();
  
  module.exports = function () {
    return new Hash();
  };
  
  /***/ })
  /******/ ]);
  });
  },{}],36:[function(require,module,exports){
  /*! safe-buffer. MIT License. Feross Aboukhadijeh <https://feross.org/opensource> */
  /* eslint-disable node/no-deprecated-api */
  var buffer = require('buffer')
  var Buffer = buffer.Buffer
  
  // alternative to using Object.keys for old browsers
  function copyProps (src, dst) {
    for (var key in src) {
      dst[key] = src[key]
    }
  }
  if (Buffer.from && Buffer.alloc && Buffer.allocUnsafe && Buffer.allocUnsafeSlow) {
    module.exports = buffer
  } else {
    // Copy properties from require('buffer')
    copyProps(buffer, exports)
    exports.Buffer = SafeBuffer
  }
  
  function SafeBuffer (arg, encodingOrOffset, length) {
    return Buffer(arg, encodingOrOffset, length)
  }
  
  SafeBuffer.prototype = Object.create(Buffer.prototype)
  
  // Copy static methods from Buffer
  copyProps(Buffer, SafeBuffer)
  
  SafeBuffer.from = function (arg, encodingOrOffset, length) {
    if (typeof arg === 'number') {
      throw new TypeError('Argument must not be a number')
    }
    return Buffer(arg, encodingOrOffset, length)
  }
  
  SafeBuffer.alloc = function (size, fill, encoding) {
    if (typeof size !== 'number') {
      throw new TypeError('Argument must be a number')
    }
    var buf = Buffer(size)
    if (fill !== undefined) {
      if (typeof encoding === 'string') {
        buf.fill(fill, encoding)
      } else {
        buf.fill(fill)
      }
    } else {
      buf.fill(0)
    }
    return buf
  }
  
  SafeBuffer.allocUnsafe = function (size) {
    if (typeof size !== 'number') {
      throw new TypeError('Argument must be a number')
    }
    return Buffer(size)
  }
  
  SafeBuffer.allocUnsafeSlow = function (size) {
    if (typeof size !== 'number') {
      throw new TypeError('Argument must be a number')
    }
    return buffer.SlowBuffer(size)
  }
  
  },{"buffer":7}],37:[function(require,module,exports){
  /*! simple-peer. MIT License. Feross Aboukhadijeh <https://feross.org/opensource> */
  const debug = require('debug')('simple-peer')
  const getBrowserRTC = require('get-browser-rtc')
  const randombytes = require('randombytes')
  const stream = require('readable-stream')
  const queueMicrotask = require('queue-microtask') // TODO: remove when Node 10 is not supported
  const errCode = require('err-code')
  const { Buffer } = require('buffer')
  
  const MAX_BUFFERED_AMOUNT = 64 * 1024
  const ICECOMPLETE_TIMEOUT = 5 * 1000
  const CHANNEL_CLOSING_TIMEOUT = 5 * 1000
  
  // HACK: Filter trickle lines when trickle is disabled #354
  function filterTrickle (sdp) {
    return sdp.replace(/a=ice-options:trickle\s\n/g, '')
  }
  
  function warn (message) {
    console.warn(message)
  }
  
  /**
   * WebRTC peer connection. Same API as node core `net.Socket`, plus a few extra methods.
   * Duplex stream.
   * @param {Object} opts
   */
  class Peer extends stream.Duplex {
    constructor (opts) {
      opts = Object.assign({
        allowHalfOpen: false
      }, opts)
  
      super(opts)
  
      this._id = randombytes(4).toString('hex').slice(0, 7)
      this._debug('new peer %o', opts)
  
      this.channelName = opts.initiator
        ? opts.channelName || randombytes(20).toString('hex')
        : null
  
      this.initiator = opts.initiator || false
      this.channelConfig = opts.channelConfig || Peer.channelConfig
      this.channelNegotiated = this.channelConfig.negotiated
      this.config = Object.assign({}, Peer.config, opts.config)
      this.offerOptions = opts.offerOptions || {}
      this.answerOptions = opts.answerOptions || {}
      this.sdpTransform = opts.sdpTransform || (sdp => sdp)
      this.streams = opts.streams || (opts.stream ? [opts.stream] : []) // support old "stream" option
      this.trickle = opts.trickle !== undefined ? opts.trickle : true
      this.allowHalfTrickle = opts.allowHalfTrickle !== undefined ? opts.allowHalfTrickle : false
      this.iceCompleteTimeout = opts.iceCompleteTimeout || ICECOMPLETE_TIMEOUT
  
      this.destroyed = false
      this.destroying = false
      this._connected = false
  
      this.remoteAddress = undefined
      this.remoteFamily = undefined
      this.remotePort = undefined
      this.localAddress = undefined
      this.localFamily = undefined
      this.localPort = undefined
  
      this._wrtc = (opts.wrtc && typeof opts.wrtc === 'object')
        ? opts.wrtc
        : getBrowserRTC()
  
      if (!this._wrtc) {
        if (typeof window === 'undefined') {
          throw errCode(new Error('No WebRTC support: Specify `opts.wrtc` option in this environment'), 'ERR_WEBRTC_SUPPORT')
        } else {
          throw errCode(new Error('No WebRTC support: Not a supported browser'), 'ERR_WEBRTC_SUPPORT')
        }
      }
  
      this._pcReady = false
      this._channelReady = false
      this._iceComplete = false // ice candidate trickle done (got null candidate)
      this._iceCompleteTimer = null // send an offer/answer anyway after some timeout
      this._channel = null
      this._pendingCandidates = []
  
      this._isNegotiating = false // is this peer waiting for negotiation to complete?
      this._firstNegotiation = true
      this._batchedNegotiation = false // batch synchronous negotiations
      this._queuedNegotiation = false // is there a queued negotiation request?
      this._sendersAwaitingStable = []
      this._senderMap = new Map()
      this._closingInterval = null
  
      this._remoteTracks = []
      this._remoteStreams = []
  
      this._chunk = null
      this._cb = null
      this._interval = null
  
      try {
        this._pc = new (this._wrtc.RTCPeerConnection)(this.config)
      } catch (err) {
        queueMicrotask(() => this.destroy(errCode(err, 'ERR_PC_CONSTRUCTOR')))
        return
      }
  
      // We prefer feature detection whenever possible, but sometimes that's not
      // possible for certain implementations.
      this._isReactNativeWebrtc = typeof this._pc._peerConnectionId === 'number'
  
      this._pc.oniceconnectionstatechange = () => {
        this._onIceStateChange()
      }
      this._pc.onicegatheringstatechange = () => {
        this._onIceStateChange()
      }
      this._pc.onconnectionstatechange = () => {
        this._onConnectionStateChange()
      }
      this._pc.onsignalingstatechange = () => {
        this._onSignalingStateChange()
      }
      this._pc.onicecandidate = event => {
        this._onIceCandidate(event)
      }
  
      // Other spec events, unused by this implementation:
      // - onconnectionstatechange
      // - onicecandidateerror
      // - onfingerprintfailure
      // - onnegotiationneeded
  
      if (this.initiator || this.channelNegotiated) {
        this._setupData({
          channel: this._pc.createDataChannel(this.channelName, this.channelConfig)
        })
      } else {
        this._pc.ondatachannel = event => {
          this._setupData(event)
        }
      }
  
      if (this.streams) {
        this.streams.forEach(stream => {
          this.addStream(stream)
        })
      }
      this._pc.ontrack = event => {
        this._onTrack(event)
      }
  
      this._debug('initial negotiation')
      this._needsNegotiation()
  
      this._onFinishBound = () => {
        this._onFinish()
      }
      this.once('finish', this._onFinishBound)
    }
  
    get bufferSize () {
      return (this._channel && this._channel.bufferedAmount) || 0
    }
  
    // HACK: it's possible channel.readyState is "closing" before peer.destroy() fires
    // https://bugs.chromium.org/p/chromium/issues/detail?id=882743
    get connected () {
      return (this._connected && this._channel.readyState === 'open')
    }
  
    address () {
      return { port: this.localPort, family: this.localFamily, address: this.localAddress }
    }
  
    signal (data) {
      if (this.destroyed) throw errCode(new Error('cannot signal after peer is destroyed'), 'ERR_SIGNALING')
      if (typeof data === 'string') {
        try {
          data = JSON.parse(data)
        } catch (err) {
          data = {}
        }
      }
      this._debug('signal()')
  
      if (data.renegotiate && this.initiator) {
        this._debug('got request to renegotiate')
        this._needsNegotiation()
      }
      if (data.transceiverRequest && this.initiator) {
        this._debug('got request for transceiver')
        this.addTransceiver(data.transceiverRequest.kind, data.transceiverRequest.init)
      }
      if (data.candidate) {
        if (this._pc.remoteDescription && this._pc.remoteDescription.type) {
          this._addIceCandidate(data.candidate)
        } else {
          this._pendingCandidates.push(data.candidate)
        }
      }
      if (data.sdp) {
        this._pc.setRemoteDescription(new (this._wrtc.RTCSessionDescription)(data))
          .then(() => {
            if (this.destroyed) return
  
            this._pendingCandidates.forEach(candidate => {
              this._addIceCandidate(candidate)
            })
            this._pendingCandidates = []
  
            if (this._pc.remoteDescription.type === 'offer') this._createAnswer()
          })
          .catch(err => {
            this.destroy(errCode(err, 'ERR_SET_REMOTE_DESCRIPTION'))
          })
      }
      if (!data.sdp && !data.candidate && !data.renegotiate && !data.transceiverRequest) {
        this.destroy(errCode(new Error('signal() called with invalid signal data'), 'ERR_SIGNALING'))
      }
    }
  
    _addIceCandidate (candidate) {
      const iceCandidateObj = new this._wrtc.RTCIceCandidate(candidate)
      this._pc.addIceCandidate(iceCandidateObj)
        .catch(err => {
          if (!iceCandidateObj.address || iceCandidateObj.address.endsWith('.local')) {
            warn('Ignoring unsupported ICE candidate.')
          } else {
            this.destroy(errCode(err, 'ERR_ADD_ICE_CANDIDATE'))
          }
        })
    }
  
    /**
     * Send text/binary data to the remote peer.
     * @param {ArrayBufferView|ArrayBuffer|Buffer|string|Blob} chunk
     */
    send (chunk) {
      this._channel.send(chunk)
    }
  
    /**
     * Add a Transceiver to the connection.
     * @param {String} kind
     * @param {Object} init
     */
    addTransceiver (kind, init) {
      this._debug('addTransceiver()')
  
      if (this.initiator) {
        try {
          this._pc.addTransceiver(kind, init)
          this._needsNegotiation()
        } catch (err) {
          this.destroy(errCode(err, 'ERR_ADD_TRANSCEIVER'))
        }
      } else {
        this.emit('signal', { // request initiator to renegotiate
          type: 'transceiverRequest',
          transceiverRequest: { kind, init }
        })
      }
    }
  
    /**
     * Add a MediaStream to the connection.
     * @param {MediaStream} stream
     */
    addStream (stream) {
      this._debug('addStream()')
  
      stream.getTracks().forEach(track => {
        this.addTrack(track, stream)
      })
    }
  
    /**
     * Add a MediaStreamTrack to the connection.
     * @param {MediaStreamTrack} track
     * @param {MediaStream} stream
     */
    addTrack (track, stream) {
      this._debug('addTrack()')
  
      const submap = this._senderMap.get(track) || new Map() // nested Maps map [track, stream] to sender
      let sender = submap.get(stream)
      if (!sender) {
        sender = this._pc.addTrack(track, stream)
        submap.set(stream, sender)
        this._senderMap.set(track, submap)
        this._needsNegotiation()
      } else if (sender.removed) {
        throw errCode(new Error('Track has been removed. You should enable/disable tracks that you want to re-add.'), 'ERR_SENDER_REMOVED')
      } else {
        throw errCode(new Error('Track has already been added to that stream.'), 'ERR_SENDER_ALREADY_ADDED')
      }
    }
  
    /**
     * Replace a MediaStreamTrack by another in the connection.
     * @param {MediaStreamTrack} oldTrack
     * @param {MediaStreamTrack} newTrack
     * @param {MediaStream} stream
     */
    replaceTrack (oldTrack, newTrack, stream) {
      this._debug('replaceTrack()')
  
      const submap = this._senderMap.get(oldTrack)
      const sender = submap ? submap.get(stream) : null
      if (!sender) {
        throw errCode(new Error('Cannot replace track that was never added.'), 'ERR_TRACK_NOT_ADDED')
      }
      if (newTrack) this._senderMap.set(newTrack, submap)
  
      if (sender.replaceTrack != null) {
        sender.replaceTrack(newTrack)
      } else {
        this.destroy(errCode(new Error('replaceTrack is not supported in this browser'), 'ERR_UNSUPPORTED_REPLACETRACK'))
      }
    }
  
    /**
     * Remove a MediaStreamTrack from the connection.
     * @param {MediaStreamTrack} track
     * @param {MediaStream} stream
     */
    removeTrack (track, stream) {
      this._debug('removeSender()')
  
      const submap = this._senderMap.get(track)
      const sender = submap ? submap.get(stream) : null
      if (!sender) {
        throw errCode(new Error('Cannot remove track that was never added.'), 'ERR_TRACK_NOT_ADDED')
      }
      try {
        sender.removed = true
        this._pc.removeTrack(sender)
      } catch (err) {
        if (err.name === 'NS_ERROR_UNEXPECTED') {
          this._sendersAwaitingStable.push(sender) // HACK: Firefox must wait until (signalingState === stable) https://bugzilla.mozilla.org/show_bug.cgi?id=1133874
        } else {
          this.destroy(errCode(err, 'ERR_REMOVE_TRACK'))
        }
      }
      this._needsNegotiation()
    }
  
    /**
     * Remove a MediaStream from the connection.
     * @param {MediaStream} stream
     */
    removeStream (stream) {
      this._debug('removeSenders()')
  
      stream.getTracks().forEach(track => {
        this.removeTrack(track, stream)
      })
    }
  
    _needsNegotiation () {
      this._debug('_needsNegotiation')
      if (this._batchedNegotiation) return // batch synchronous renegotiations
      this._batchedNegotiation = true
      queueMicrotask(() => {
        this._batchedNegotiation = false
        if (this.initiator || !this._firstNegotiation) {
          this._debug('starting batched negotiation')
          this.negotiate()
        } else {
          this._debug('non-initiator initial negotiation request discarded')
        }
        this._firstNegotiation = false
      })
    }
  
    negotiate () {
      if (this.initiator) {
        if (this._isNegotiating) {
          this._queuedNegotiation = true
          this._debug('already negotiating, queueing')
        } else {
          this._debug('start negotiation')
          setTimeout(() => { // HACK: Chrome crashes if we immediately call createOffer
            this._createOffer()
          }, 0)
        }
      } else {
        if (this._isNegotiating) {
          this._queuedNegotiation = true
          this._debug('already negotiating, queueing')
        } else {
          this._debug('requesting negotiation from initiator')
          this.emit('signal', { // request initiator to renegotiate
            type: 'renegotiate',
            renegotiate: true
          })
        }
      }
      this._isNegotiating = true
    }
  
    // TODO: Delete this method once readable-stream is updated to contain a default
    // implementation of destroy() that automatically calls _destroy()
    // See: https://github.com/nodejs/readable-stream/issues/283
    destroy (err) {
      this._destroy(err, () => {})
    }
  
    _destroy (err, cb) {
      if (this.destroyed || this.destroying) return
      this.destroying = true
  
      this._debug('destroying (error: %s)', err && (err.message || err))
  
      queueMicrotask(() => { // allow events concurrent with the call to _destroy() to fire (see #692)
        this.destroyed = true
        this.destroying = false
  
        this._debug('destroy (error: %s)', err && (err.message || err))
  
        this.readable = this.writable = false
  
        if (!this._readableState.ended) this.push(null)
        if (!this._writableState.finished) this.end()
  
        this._connected = false
        this._pcReady = false
        this._channelReady = false
        this._remoteTracks = null
        this._remoteStreams = null
        this._senderMap = null
  
        clearInterval(this._closingInterval)
        this._closingInterval = null
  
        clearInterval(this._interval)
        this._interval = null
        this._chunk = null
        this._cb = null
  
        if (this._onFinishBound) this.removeListener('finish', this._onFinishBound)
        this._onFinishBound = null
  
        if (this._channel) {
          try {
            this._channel.close()
          } catch (err) {}
  
          // allow events concurrent with destruction to be handled
          this._channel.onmessage = null
          this._channel.onopen = null
          this._channel.onclose = null
          this._channel.onerror = null
        }
        if (this._pc) {
          try {
            this._pc.close()
          } catch (err) {}
  
          // allow events concurrent with destruction to be handled
          this._pc.oniceconnectionstatechange = null
          this._pc.onicegatheringstatechange = null
          this._pc.onsignalingstatechange = null
          this._pc.onicecandidate = null
          this._pc.ontrack = null
          this._pc.ondatachannel = null
        }
        this._pc = null
        this._channel = null
  
        if (err) this.emit('error', err)
        this.emit('close')
        cb()
      })
    }
  
    _setupData (event) {
      if (!event.channel) {
        // In some situations `pc.createDataChannel()` returns `undefined` (in wrtc),
        // which is invalid behavior. Handle it gracefully.
        // See: https://github.com/feross/simple-peer/issues/163
        return this.destroy(errCode(new Error('Data channel event is missing `channel` property'), 'ERR_DATA_CHANNEL'))
      }
  
      this._channel = event.channel
      this._channel.binaryType = 'arraybuffer'
  
      if (typeof this._channel.bufferedAmountLowThreshold === 'number') {
        this._channel.bufferedAmountLowThreshold = MAX_BUFFERED_AMOUNT
      }
  
      this.channelName = this._channel.label
  
      this._channel.onmessage = event => {
        this._onChannelMessage(event)
      }
      this._channel.onbufferedamountlow = () => {
        this._onChannelBufferedAmountLow()
      }
      this._channel.onopen = () => {
        this._onChannelOpen()
      }
      this._channel.onclose = () => {
        this._onChannelClose()
      }
      this._channel.onerror = err => {
        this.destroy(errCode(err, 'ERR_DATA_CHANNEL'))
      }
  
      // HACK: Chrome will sometimes get stuck in readyState "closing", let's check for this condition
      // https://bugs.chromium.org/p/chromium/issues/detail?id=882743
      let isClosing = false
      this._closingInterval = setInterval(() => { // No "onclosing" event
        if (this._channel && this._channel.readyState === 'closing') {
          if (isClosing) this._onChannelClose() // closing timed out: equivalent to onclose firing
          isClosing = true
        } else {
          isClosing = false
        }
      }, CHANNEL_CLOSING_TIMEOUT)
    }
  
    _read () {}
  
    _write (chunk, encoding, cb) {
      if (this.destroyed) return cb(errCode(new Error('cannot write after peer is destroyed'), 'ERR_DATA_CHANNEL'))
  
      if (this._connected) {
        try {
          this.send(chunk)
        } catch (err) {
          return this.destroy(errCode(err, 'ERR_DATA_CHANNEL'))
        }
        if (this._channel.bufferedAmount > MAX_BUFFERED_AMOUNT) {
          this._debug('start backpressure: bufferedAmount %d', this._channel.bufferedAmount)
          this._cb = cb
        } else {
          cb(null)
        }
      } else {
        this._debug('write before connect')
        this._chunk = chunk
        this._cb = cb
      }
    }
  
    // When stream finishes writing, close socket. Half open connections are not
    // supported.
    _onFinish () {
      if (this.destroyed) return
  
      // Wait a bit before destroying so the socket flushes.
      // TODO: is there a more reliable way to accomplish this?
      const destroySoon = () => {
        setTimeout(() => this.destroy(), 1000)
      }
  
      if (this._connected) {
        destroySoon()
      } else {
        this.once('connect', destroySoon)
      }
    }
  
    _startIceCompleteTimeout () {
      if (this.destroyed) return
      if (this._iceCompleteTimer) return
      this._debug('started iceComplete timeout')
      this._iceCompleteTimer = setTimeout(() => {
        if (!this._iceComplete) {
          this._iceComplete = true
          this._debug('iceComplete timeout completed')
          this.emit('iceTimeout')
          this.emit('_iceComplete')
        }
      }, this.iceCompleteTimeout)
    }
  
    _createOffer () {
      if (this.destroyed) return
  
      this._pc.createOffer(this.offerOptions)
        .then(offer => {
          if (this.destroyed) return
          if (!this.trickle && !this.allowHalfTrickle) offer.sdp = filterTrickle(offer.sdp)
          offer.sdp = this.sdpTransform(offer.sdp)
  
          const sendOffer = () => {
            if (this.destroyed) return
            const signal = this._pc.localDescription || offer
            this._debug('signal')
            this.emit('signal', {
              type: signal.type,
              sdp: signal.sdp
            })
          }
  
          const onSuccess = () => {
            this._debug('createOffer success')
            if (this.destroyed) return
            if (this.trickle || this._iceComplete) sendOffer()
            else this.once('_iceComplete', sendOffer) // wait for candidates
          }
  
          const onError = err => {
            this.destroy(errCode(err, 'ERR_SET_LOCAL_DESCRIPTION'))
          }
  
          this._pc.setLocalDescription(offer)
            .then(onSuccess)
            .catch(onError)
        })
        .catch(err => {
          this.destroy(errCode(err, 'ERR_CREATE_OFFER'))
        })
    }
  
    _requestMissingTransceivers () {
      if (this._pc.getTransceivers) {
        this._pc.getTransceivers().forEach(transceiver => {
          if (!transceiver.mid && transceiver.sender.track && !transceiver.requested) {
            transceiver.requested = true // HACK: Safari returns negotiated transceivers with a null mid
            this.addTransceiver(transceiver.sender.track.kind)
          }
        })
      }
    }
  
    _createAnswer () {
      if (this.destroyed) return
  
      this._pc.createAnswer(this.answerOptions)
        .then(answer => {
          if (this.destroyed) return
          if (!this.trickle && !this.allowHalfTrickle) answer.sdp = filterTrickle(answer.sdp)
          answer.sdp = this.sdpTransform(answer.sdp)
  
          const sendAnswer = () => {
            if (this.destroyed) return
            const signal = this._pc.localDescription || answer
            this._debug('signal')
            this.emit('signal', {
              type: signal.type,
              sdp: signal.sdp
            })
            if (!this.initiator) this._requestMissingTransceivers()
          }
  
          const onSuccess = () => {
            if (this.destroyed) return
            if (this.trickle || this._iceComplete) sendAnswer()
            else this.once('_iceComplete', sendAnswer)
          }
  
          const onError = err => {
            this.destroy(errCode(err, 'ERR_SET_LOCAL_DESCRIPTION'))
          }
  
          this._pc.setLocalDescription(answer)
            .then(onSuccess)
            .catch(onError)
        })
        .catch(err => {
          this.destroy(errCode(err, 'ERR_CREATE_ANSWER'))
        })
    }
  
    _onConnectionStateChange () {
      if (this.destroyed) return
      if (this._pc.connectionState === 'failed') {
        this.destroy(errCode(new Error('Connection failed.'), 'ERR_CONNECTION_FAILURE'))
      }
    }
  
    _onIceStateChange () {
      if (this.destroyed) return
      const iceConnectionState = this._pc.iceConnectionState
      const iceGatheringState = this._pc.iceGatheringState
  
      this._debug(
        'iceStateChange (connection: %s) (gathering: %s)',
        iceConnectionState,
        iceGatheringState
      )
      this.emit('iceStateChange', iceConnectionState, iceGatheringState)
  
      if (iceConnectionState === 'connected' || iceConnectionState === 'completed') {
        this._pcReady = true
        this._maybeReady()
      }
      if (iceConnectionState === 'failed') {
        this.destroy(errCode(new Error('Ice connection failed.'), 'ERR_ICE_CONNECTION_FAILURE'))
      }
      if (iceConnectionState === 'closed') {
        this.destroy(errCode(new Error('Ice connection closed.'), 'ERR_ICE_CONNECTION_CLOSED'))
      }
    }
  
    getStats (cb) {
      // statreports can come with a value array instead of properties
      const flattenValues = report => {
        if (Object.prototype.toString.call(report.values) === '[object Array]') {
          report.values.forEach(value => {
            Object.assign(report, value)
          })
        }
        return report
      }
  
      // Promise-based getStats() (standard)
      if (this._pc.getStats.length === 0 || this._isReactNativeWebrtc) {
        this._pc.getStats()
          .then(res => {
            const reports = []
            res.forEach(report => {
              reports.push(flattenValues(report))
            })
            cb(null, reports)
          }, err => cb(err))
  
      // Single-parameter callback-based getStats() (non-standard)
      } else if (this._pc.getStats.length > 0) {
        this._pc.getStats(res => {
          // If we destroy connection in `connect` callback this code might happen to run when actual connection is already closed
          if (this.destroyed) return
  
          const reports = []
          res.result().forEach(result => {
            const report = {}
            result.names().forEach(name => {
              report[name] = result.stat(name)
            })
            report.id = result.id
            report.type = result.type
            report.timestamp = result.timestamp
            reports.push(flattenValues(report))
          })
          cb(null, reports)
        }, err => cb(err))
  
      // Unknown browser, skip getStats() since it's anyone's guess which style of
      // getStats() they implement.
      } else {
        cb(null, [])
      }
    }
  
    _maybeReady () {
      this._debug('maybeReady pc %s channel %s', this._pcReady, this._channelReady)
      if (this._connected || this._connecting || !this._pcReady || !this._channelReady) return
  
      this._connecting = true
  
      // HACK: We can't rely on order here, for details see https://github.com/js-platform/node-webrtc/issues/339
      const findCandidatePair = () => {
        if (this.destroyed) return
  
        this.getStats((err, items) => {
          if (this.destroyed) return
  
          // Treat getStats error as non-fatal. It's not essential.
          if (err) items = []
  
          const remoteCandidates = {}
          const localCandidates = {}
          const candidatePairs = {}
          let foundSelectedCandidatePair = false
  
          items.forEach(item => {
            // TODO: Once all browsers support the hyphenated stats report types, remove
            // the non-hypenated ones
            if (item.type === 'remotecandidate' || item.type === 'remote-candidate') {
              remoteCandidates[item.id] = item
            }
            if (item.type === 'localcandidate' || item.type === 'local-candidate') {
              localCandidates[item.id] = item
            }
            if (item.type === 'candidatepair' || item.type === 'candidate-pair') {
              candidatePairs[item.id] = item
            }
          })
  
          const setSelectedCandidatePair = selectedCandidatePair => {
            foundSelectedCandidatePair = true
  
            let local = localCandidates[selectedCandidatePair.localCandidateId]
  
            if (local && (local.ip || local.address)) {
              // Spec
              this.localAddress = local.ip || local.address
              this.localPort = Number(local.port)
            } else if (local && local.ipAddress) {
              // Firefox
              this.localAddress = local.ipAddress
              this.localPort = Number(local.portNumber)
            } else if (typeof selectedCandidatePair.googLocalAddress === 'string') {
              // TODO: remove this once Chrome 58 is released
              local = selectedCandidatePair.googLocalAddress.split(':')
              this.localAddress = local[0]
              this.localPort = Number(local[1])
            }
            if (this.localAddress) {
              this.localFamily = this.localAddress.includes(':') ? 'IPv6' : 'IPv4'
            }
  
            let remote = remoteCandidates[selectedCandidatePair.remoteCandidateId]
  
            if (remote && (remote.ip || remote.address)) {
              // Spec
              this.remoteAddress = remote.ip || remote.address
              this.remotePort = Number(remote.port)
            } else if (remote && remote.ipAddress) {
              // Firefox
              this.remoteAddress = remote.ipAddress
              this.remotePort = Number(remote.portNumber)
            } else if (typeof selectedCandidatePair.googRemoteAddress === 'string') {
              // TODO: remove this once Chrome 58 is released
              remote = selectedCandidatePair.googRemoteAddress.split(':')
              this.remoteAddress = remote[0]
              this.remotePort = Number(remote[1])
            }
            if (this.remoteAddress) {
              this.remoteFamily = this.remoteAddress.includes(':') ? 'IPv6' : 'IPv4'
            }
  
            this._debug(
              'connect local: %s:%s remote: %s:%s',
              this.localAddress,
              this.localPort,
              this.remoteAddress,
              this.remotePort
            )
          }
  
          items.forEach(item => {
            // Spec-compliant
            if (item.type === 'transport' && item.selectedCandidatePairId) {
              setSelectedCandidatePair(candidatePairs[item.selectedCandidatePairId])
            }
  
            // Old implementations
            if (
              (item.type === 'googCandidatePair' && item.googActiveConnection === 'true') ||
              ((item.type === 'candidatepair' || item.type === 'candidate-pair') && item.selected)
            ) {
              setSelectedCandidatePair(item)
            }
          })
  
          // Ignore candidate pair selection in browsers like Safari 11 that do not have any local or remote candidates
          // But wait until at least 1 candidate pair is available
          if (!foundSelectedCandidatePair && (!Object.keys(candidatePairs).length || Object.keys(localCandidates).length)) {
            setTimeout(findCandidatePair, 100)
            return
          } else {
            this._connecting = false
            this._connected = true
          }
  
          if (this._chunk) {
            try {
              this.send(this._chunk)
            } catch (err) {
              return this.destroy(errCode(err, 'ERR_DATA_CHANNEL'))
            }
            this._chunk = null
            this._debug('sent chunk from "write before connect"')
  
            const cb = this._cb
            this._cb = null
            cb(null)
          }
  
          // If `bufferedAmountLowThreshold` and 'onbufferedamountlow' are unsupported,
          // fallback to using setInterval to implement backpressure.
          if (typeof this._channel.bufferedAmountLowThreshold !== 'number') {
            this._interval = setInterval(() => this._onInterval(), 150)
            if (this._interval.unref) this._interval.unref()
          }
  
          this._debug('connect')
          this.emit('connect')
        })
      }
      findCandidatePair()
    }
  
    _onInterval () {
      if (!this._cb || !this._channel || this._channel.bufferedAmount > MAX_BUFFERED_AMOUNT) {
        return
      }
      this._onChannelBufferedAmountLow()
    }
  
    _onSignalingStateChange () {
      if (this.destroyed) return
  
      if (this._pc.signalingState === 'stable') {
        this._isNegotiating = false
  
        // HACK: Firefox doesn't yet support removing tracks when signalingState !== 'stable'
        this._debug('flushing sender queue', this._sendersAwaitingStable)
        this._sendersAwaitingStable.forEach(sender => {
          this._pc.removeTrack(sender)
          this._queuedNegotiation = true
        })
        this._sendersAwaitingStable = []
  
        if (this._queuedNegotiation) {
          this._debug('flushing negotiation queue')
          this._queuedNegotiation = false
          this._needsNegotiation() // negotiate again
        } else {
          this._debug('negotiated')
          this.emit('negotiated')
        }
      }
  
      this._debug('signalingStateChange %s', this._pc.signalingState)
      this.emit('signalingStateChange', this._pc.signalingState)
    }
  
    _onIceCandidate (event) {
      if (this.destroyed) return
      if (event.candidate && this.trickle) {
        this.emit('signal', {
          type: 'candidate',
          candidate: {
            candidate: event.candidate.candidate,
            sdpMLineIndex: event.candidate.sdpMLineIndex,
            sdpMid: event.candidate.sdpMid
          }
        })
      } else if (!event.candidate && !this._iceComplete) {
        this._iceComplete = true
        this.emit('_iceComplete')
      }
      // as soon as we've received one valid candidate start timeout
      if (event.candidate) {
        this._startIceCompleteTimeout()
      }
    }
  
    _onChannelMessage (event) {
      if (this.destroyed) return
      let data = event.data
      if (data instanceof ArrayBuffer) data = Buffer.from(data)
      this.push(data)
    }
  
    _onChannelBufferedAmountLow () {
      if (this.destroyed || !this._cb) return
      this._debug('ending backpressure: bufferedAmount %d', this._channel.bufferedAmount)
      const cb = this._cb
      this._cb = null
      cb(null)
    }
  
    _onChannelOpen () {
      if (this._connected || this.destroyed) return
      this._debug('on channel open')
      this._channelReady = true
      this._maybeReady()
    }
  
    _onChannelClose () {
      if (this.destroyed) return
      this._debug('on channel close')
      this.destroy()
    }
  
    _onTrack (event) {
      if (this.destroyed) return
  
      event.streams.forEach(eventStream => {
        this._debug('on track')
        this.emit('track', event.track, eventStream)
  
        this._remoteTracks.push({
          track: event.track,
          stream: eventStream
        })
  
        if (this._remoteStreams.some(remoteStream => {
          return remoteStream.id === eventStream.id
        })) return // Only fire one 'stream' event, even though there may be multiple tracks per stream
  
        this._remoteStreams.push(eventStream)
        queueMicrotask(() => {
          this._debug('on stream')
          this.emit('stream', eventStream) // ensure all tracks have been added
        })
      })
    }
  
    _debug () {
      const args = [].slice.call(arguments)
      args[0] = '[' + this._id + '] ' + args[0]
      debug.apply(null, args)
    }
  }
  
  Peer.WEBRTC_SUPPORT = !!getBrowserRTC()
  
  /**
   * Expose peer and data channel config for overriding all Peer
   * instances. Otherwise, just set opts.config or opts.channelConfig
   * when constructing a Peer.
   */
  Peer.config = {
    iceServers: [
      {
        urls: [
          'stun:stun.l.google.com:19302',
          'stun:global.stun.twilio.com:3478'
        ]
      }
    ],
    sdpSemantics: 'unified-plan'
  }
  
  Peer.channelConfig = {}
  
  module.exports = Peer
  
  },{"buffer":7,"debug":9,"err-code":11,"get-browser-rtc":12,"queue-microtask":18,"randombytes":19,"readable-stream":34}],38:[function(require,module,exports){
  /* global self */
  
  var Rusha = require('rusha')
  var rushaWorkerSha1 = require('./rusha-worker-sha1')
  
  var rusha = new Rusha()
  var scope = typeof window !== 'undefined' ? window : self
  var crypto = scope.crypto || scope.msCrypto || {}
  var subtle = crypto.subtle || crypto.webkitSubtle
  
  function sha1sync (buf) {
    return rusha.digest(buf)
  }
  
  // Browsers throw if they lack support for an algorithm.
  // Promise will be rejected on non-secure origins. (http://goo.gl/lq4gCo)
  try {
    subtle.digest({ name: 'sha-1' }, new Uint8Array()).catch(function () {
      subtle = false
    })
  } catch (err) { subtle = false }
  
  function sha1 (buf, cb) {
    if (!subtle) {
      if (typeof window !== 'undefined') {
        rushaWorkerSha1(buf, function onRushaWorkerSha1 (err, hash) {
          if (err) {
            // On error, fallback to synchronous method which cannot fail
            cb(sha1sync(buf))
            return
          }
  
          cb(hash)
        })
      } else {
        queueMicrotask(() => cb(sha1sync(buf)))
      }
      return
    }
  
    if (typeof buf === 'string') {
      buf = uint8array(buf)
    }
  
    subtle.digest({ name: 'sha-1' }, buf)
      .then(function succeed (result) {
        cb(hex(new Uint8Array(result)))
      },
      function fail () {
        // On error, fallback to synchronous method which cannot fail
        cb(sha1sync(buf))
      })
  }
  
  function uint8array (s) {
    var l = s.length
    var array = new Uint8Array(l)
    for (var i = 0; i < l; i++) {
      array[i] = s.charCodeAt(i)
    }
    return array
  }
  
  function hex (buf) {
    var l = buf.length
    var chars = []
    for (var i = 0; i < l; i++) {
      var bite = buf[i]
      chars.push((bite >>> 4).toString(16))
      chars.push((bite & 0x0f).toString(16))
    }
    return chars.join('')
  }
  
  module.exports = sha1
  module.exports.sync = sha1sync
  
  },{"./rusha-worker-sha1":39,"rusha":35}],39:[function(require,module,exports){
  var Rusha = require('rusha')
  
  var worker
  var nextTaskId
  var cbs
  
  function init () {
    worker = Rusha.createWorker()
    nextTaskId = 1
    cbs = {} // taskId -> cb
  
    worker.onmessage = function onRushaMessage (e) {
      var taskId = e.data.id
      var cb = cbs[taskId]
      delete cbs[taskId]
  
      if (e.data.error != null) {
        cb(new Error('Rusha worker error: ' + e.data.error))
      } else {
        cb(null, e.data.hash)
      }
    }
  }
  
  function sha1 (buf, cb) {
    if (!worker) init()
  
    cbs[nextTaskId] = cb
    worker.postMessage({ id: nextTaskId, data: buf })
    nextTaskId += 1
  }
  
  module.exports = sha1
  
  },{"rusha":35}],40:[function(require,module,exports){
  (function (Buffer){(function (){
  /* global WebSocket, DOMException */
  
  const debug = require('debug')('simple-websocket')
  const randombytes = require('randombytes')
  const stream = require('readable-stream')
  const queueMicrotask = require('queue-microtask') // TODO: remove when Node 10 is not supported
  const ws = require('ws') // websockets in node - will be empty object in browser
  
  const _WebSocket = typeof ws !== 'function' ? WebSocket : ws
  
  const MAX_BUFFERED_AMOUNT = 64 * 1024
  
  /**
   * WebSocket. Same API as node core `net.Socket`. Duplex stream.
   * @param {Object} opts
   * @param {string=} opts.url websocket server url
   * @param {string=} opts.socket raw websocket instance to wrap
   */
  class Socket extends stream.Duplex {
    constructor (opts = {}) {
      // Support simple usage: `new Socket(url)`
      if (typeof opts === 'string') {
        opts = { url: opts }
      }
  
      opts = Object.assign({
        allowHalfOpen: false
      }, opts)
  
      super(opts)
  
      if (opts.url == null && opts.socket == null) {
        throw new Error('Missing required `url` or `socket` option')
      }
      if (opts.url != null && opts.socket != null) {
        throw new Error('Must specify either `url` or `socket` option, not both')
      }
  
      this._id = randombytes(4).toString('hex').slice(0, 7)
      this._debug('new websocket: %o', opts)
  
      this.connected = false
      this.destroyed = false
  
      this._chunk = null
      this._cb = null
      this._interval = null
  
      if (opts.socket) {
        this.url = opts.socket.url
        this._ws = opts.socket
        this.connected = opts.socket.readyState === _WebSocket.OPEN
      } else {
        this.url = opts.url
        try {
          if (typeof ws === 'function') {
            // `ws` package accepts options
            this._ws = new _WebSocket(opts.url, opts)
          } else {
            this._ws = new _WebSocket(opts.url)
          }
        } catch (err) {
          queueMicrotask(() => this.destroy(err))
          return
        }
      }
  
      this._ws.binaryType = 'arraybuffer'
      this._ws.onopen = () => {
        this._onOpen()
      }
      this._ws.onmessage = event => {
        this._onMessage(event)
      }
      this._ws.onclose = () => {
        this._onClose()
      }
      this._ws.onerror = () => {
        this.destroy(new Error('connection error to ' + this.url))
      }
  
      this._onFinishBound = () => {
        this._onFinish()
      }
      this.once('finish', this._onFinishBound)
    }
  
    /**
     * Send text/binary data to the WebSocket server.
     * @param {TypedArrayView|ArrayBuffer|Buffer|string|Blob|Object} chunk
     */
    send (chunk) {
      this._ws.send(chunk)
    }
  
    // TODO: Delete this method once readable-stream is updated to contain a default
    // implementation of destroy() that automatically calls _destroy()
    // See: https://github.com/nodejs/readable-stream/issues/283
    destroy (err) {
      this._destroy(err, () => {})
    }
  
    _destroy (err, cb) {
      if (this.destroyed) return
  
      this._debug('destroy (error: %s)', err && (err.message || err))
  
      this.readable = this.writable = false
      if (!this._readableState.ended) this.push(null)
      if (!this._writableState.finished) this.end()
  
      this.connected = false
      this.destroyed = true
  
      clearInterval(this._interval)
      this._interval = null
      this._chunk = null
      this._cb = null
  
      if (this._onFinishBound) this.removeListener('finish', this._onFinishBound)
      this._onFinishBound = null
  
      if (this._ws) {
        const ws = this._ws
        const onClose = () => {
          ws.onclose = null
        }
        if (ws.readyState === _WebSocket.CLOSED) {
          onClose()
        } else {
          try {
            ws.onclose = onClose
            ws.close()
          } catch (err) {
            onClose()
          }
        }
  
        ws.onopen = null
        ws.onmessage = null
        ws.onerror = () => {}
      }
      this._ws = null
  
      if (err) {
        if (typeof DOMException !== 'undefined' && err instanceof DOMException) {
          // Convert Edge DOMException object to Error object
          const code = err.code
          err = new Error(err.message)
          err.code = code
        }
        this.emit('error', err)
      }
      this.emit('close')
      cb()
    }
  
    _read () {}
  
    _write (chunk, encoding, cb) {
      if (this.destroyed) return cb(new Error('cannot write after socket is destroyed'))
  
      if (this.connected) {
        try {
          this.send(chunk)
        } catch (err) {
          return this.destroy(err)
        }
        if (typeof ws !== 'function' && this._ws.bufferedAmount > MAX_BUFFERED_AMOUNT) {
          this._debug('start backpressure: bufferedAmount %d', this._ws.bufferedAmount)
          this._cb = cb
        } else {
          cb(null)
        }
      } else {
        this._debug('write before connect')
        this._chunk = chunk
        this._cb = cb
      }
    }
  
    // When stream finishes writing, close socket. Half open connections are not
    // supported.
    _onFinish () {
      if (this.destroyed) return
  
      // Wait a bit before destroying so the socket flushes.
      // TODO: is there a more reliable way to accomplish this?
      const destroySoon = () => {
        setTimeout(() => this.destroy(), 1000)
      }
  
      if (this.connected) {
        destroySoon()
      } else {
        this.once('connect', destroySoon)
      }
    }
  
    _onMessage (event) {
      if (this.destroyed) return
      let data = event.data
      if (data instanceof ArrayBuffer) data = Buffer.from(data)
      this.push(data)
    }
  
    _onOpen () {
      if (this.connected || this.destroyed) return
      this.connected = true
  
      if (this._chunk) {
        try {
          this.send(this._chunk)
        } catch (err) {
          return this.destroy(err)
        }
        this._chunk = null
        this._debug('sent chunk from "write before connect"')
  
        const cb = this._cb
        this._cb = null
        cb(null)
      }
  
      // Backpressure is not implemented in Node.js. The `ws` module has a buggy
      // `bufferedAmount` property. See: https://github.com/websockets/ws/issues/492
      if (typeof ws !== 'function') {
        this._interval = setInterval(() => this._onInterval(), 150)
        if (this._interval.unref) this._interval.unref()
      }
  
      this._debug('connect')
      this.emit('connect')
    }
  
    _onInterval () {
      if (!this._cb || !this._ws || this._ws.bufferedAmount > MAX_BUFFERED_AMOUNT) {
        return
      }
      this._debug('ending backpressure: bufferedAmount %d', this._ws.bufferedAmount)
      const cb = this._cb
      this._cb = null
      cb(null)
    }
  
    _onClose () {
      if (this.destroyed) return
      this._debug('on close')
      this.destroy()
    }
  
    _debug () {
      const args = [].slice.call(arguments)
      args[0] = '[' + this._id + '] ' + args[0]
      debug.apply(null, args)
    }
  }
  
  Socket.WEBSOCKET_SUPPORT = !!_WebSocket
  
  module.exports = Socket
  
  }).call(this)}).call(this,require("buffer").Buffer)
  
  },{"buffer":7,"debug":9,"queue-microtask":18,"randombytes":19,"readable-stream":34,"ws":6}],41:[function(require,module,exports){
  // Copyright Joyent, Inc. and other Node contributors.
  //
  // Permission is hereby granted, free of charge, to any person obtaining a
  // copy of this software and associated documentation files (the
  // "Software"), to deal in the Software without restriction, including
  // without limitation the rights to use, copy, modify, merge, publish,
  // distribute, sublicense, and/or sell copies of the Software, and to permit
  // persons to whom the Software is furnished to do so, subject to the
  // following conditions:
  //
  // The above copyright notice and this permission notice shall be included
  // in all copies or substantial portions of the Software.
  //
  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  // OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
  // NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
  // DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
  // OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
  // USE OR OTHER DEALINGS IN THE SOFTWARE.
  
  'use strict';
  
  /*<replacement>*/
  
  var Buffer = require('safe-buffer').Buffer;
  /*</replacement>*/
  
  var isEncoding = Buffer.isEncoding || function (encoding) {
    encoding = '' + encoding;
    switch (encoding && encoding.toLowerCase()) {
      case 'hex':case 'utf8':case 'utf-8':case 'ascii':case 'binary':case 'base64':case 'ucs2':case 'ucs-2':case 'utf16le':case 'utf-16le':case 'raw':
        return true;
      default:
        return false;
    }
  };
  
  function _normalizeEncoding(enc) {
    if (!enc) return 'utf8';
    var retried;
    while (true) {
      switch (enc) {
        case 'utf8':
        case 'utf-8':
          return 'utf8';
        case 'ucs2':
        case 'ucs-2':
        case 'utf16le':
        case 'utf-16le':
          return 'utf16le';
        case 'latin1':
        case 'binary':
          return 'latin1';
        case 'base64':
        case 'ascii':
        case 'hex':
          return enc;
        default:
          if (retried) return; // undefined
          enc = ('' + enc).toLowerCase();
          retried = true;
      }
    }
  };
  
  // Do not cache `Buffer.isEncoding` when checking encoding names as some
  // modules monkey-patch it to support additional encodings
  function normalizeEncoding(enc) {
    var nenc = _normalizeEncoding(enc);
    if (typeof nenc !== 'string' && (Buffer.isEncoding === isEncoding || !isEncoding(enc))) throw new Error('Unknown encoding: ' + enc);
    return nenc || enc;
  }
  
  // StringDecoder provides an interface for efficiently splitting a series of
  // buffers into a series of JS strings without breaking apart multi-byte
  // characters.
  exports.StringDecoder = StringDecoder;
  function StringDecoder(encoding) {
    this.encoding = normalizeEncoding(encoding);
    var nb;
    switch (this.encoding) {
      case 'utf16le':
        this.text = utf16Text;
        this.end = utf16End;
        nb = 4;
        break;
      case 'utf8':
        this.fillLast = utf8FillLast;
        nb = 4;
        break;
      case 'base64':
        this.text = base64Text;
        this.end = base64End;
        nb = 3;
        break;
      default:
        this.write = simpleWrite;
        this.end = simpleEnd;
        return;
    }
    this.lastNeed = 0;
    this.lastTotal = 0;
    this.lastChar = Buffer.allocUnsafe(nb);
  }
  
  StringDecoder.prototype.write = function (buf) {
    if (buf.length === 0) return '';
    var r;
    var i;
    if (this.lastNeed) {
      r = this.fillLast(buf);
      if (r === undefined) return '';
      i = this.lastNeed;
      this.lastNeed = 0;
    } else {
      i = 0;
    }
    if (i < buf.length) return r ? r + this.text(buf, i) : this.text(buf, i);
    return r || '';
  };
  
  StringDecoder.prototype.end = utf8End;
  
  // Returns only complete characters in a Buffer
  StringDecoder.prototype.text = utf8Text;
  
  // Attempts to complete a partial non-UTF-8 character using bytes from a Buffer
  StringDecoder.prototype.fillLast = function (buf) {
    if (this.lastNeed <= buf.length) {
      buf.copy(this.lastChar, this.lastTotal - this.lastNeed, 0, this.lastNeed);
      return this.lastChar.toString(this.encoding, 0, this.lastTotal);
    }
    buf.copy(this.lastChar, this.lastTotal - this.lastNeed, 0, buf.length);
    this.lastNeed -= buf.length;
  };
  
  // Checks the type of a UTF-8 byte, whether it's ASCII, a leading byte, or a
  // continuation byte. If an invalid byte is detected, -2 is returned.
  function utf8CheckByte(byte) {
    if (byte <= 0x7F) return 0;else if (byte >> 5 === 0x06) return 2;else if (byte >> 4 === 0x0E) return 3;else if (byte >> 3 === 0x1E) return 4;
    return byte >> 6 === 0x02 ? -1 : -2;
  }
  
  // Checks at most 3 bytes at the end of a Buffer in order to detect an
  // incomplete multi-byte UTF-8 character. The total number of bytes (2, 3, or 4)
  // needed to complete the UTF-8 character (if applicable) are returned.
  function utf8CheckIncomplete(self, buf, i) {
    var j = buf.length - 1;
    if (j < i) return 0;
    var nb = utf8CheckByte(buf[j]);
    if (nb >= 0) {
      if (nb > 0) self.lastNeed = nb - 1;
      return nb;
    }
    if (--j < i || nb === -2) return 0;
    nb = utf8CheckByte(buf[j]);
    if (nb >= 0) {
      if (nb > 0) self.lastNeed = nb - 2;
      return nb;
    }
    if (--j < i || nb === -2) return 0;
    nb = utf8CheckByte(buf[j]);
    if (nb >= 0) {
      if (nb > 0) {
        if (nb === 2) nb = 0;else self.lastNeed = nb - 3;
      }
      return nb;
    }
    return 0;
  }
  function utf8CheckExtraBytes(self, buf, p) {
    if ((buf[0] & 0xC0) !== 0x80) {
      self.lastNeed = 0;
      return '\ufffd';
    }
    if (self.lastNeed > 1 && buf.length > 1) {
      if ((buf[1] & 0xC0) !== 0x80) {
        self.lastNeed = 1;
        return '\ufffd';
      }
      if (self.lastNeed > 2 && buf.length > 2) {
        if ((buf[2] & 0xC0) !== 0x80) {
          self.lastNeed = 2;
          return '\ufffd';
        }
      }
    }
  }
  function utf8FillLast(buf) {
    var p = this.lastTotal - this.lastNeed;
    var r = utf8CheckExtraBytes(this, buf, p);
    if (r !== undefined) return r;
    if (this.lastNeed <= buf.length) {
      buf.copy(this.lastChar, p, 0, this.lastNeed);
      return this.lastChar.toString(this.encoding, 0, this.lastTotal);
    }
    buf.copy(this.lastChar, p, 0, buf.length);
    this.lastNeed -= buf.length;
  }
  function utf8Text(buf, i) {
    var total = utf8CheckIncomplete(this, buf, i);
    if (!this.lastNeed) return buf.toString('utf8', i);
    this.lastTotal = total;
    var end = buf.length - (total - this.lastNeed);
    buf.copy(this.lastChar, 0, end);
    return buf.toString('utf8', i, end);
  }
  
  // For UTF-8, a replacement character is added when ending on a partial
  // character.
  function utf8End(buf) {
    var r = buf && buf.length ? this.write(buf) : '';
    if (this.lastNeed) return r + '\ufffd';
    return r;
  }
  function utf16Text(buf, i) {
    if ((buf.length - i) % 2 === 0) {
      var r = buf.toString('utf16le', i);
      if (r) {
        var c = r.charCodeAt(r.length - 1);
        if (c >= 0xD800 && c <= 0xDBFF) {
          this.lastNeed = 2;
          this.lastTotal = 4;
          this.lastChar[0] = buf[buf.length - 2];
          this.lastChar[1] = buf[buf.length - 1];
          return r.slice(0, -1);
        }
      }
      return r;
    }
    this.lastNeed = 1;
    this.lastTotal = 2;
    this.lastChar[0] = buf[buf.length - 1];
    return buf.toString('utf16le', i, buf.length - 1);
  }
  
  // For UTF-16LE we do not explicitly append special replacement characters if we
  // end on a partial character, we simply let v8 handle that.
  function utf16End(buf) {
    var r = buf && buf.length ? this.write(buf) : '';
    if (this.lastNeed) {
      var end = this.lastTotal - this.lastNeed;
      return r + this.lastChar.toString('utf16le', 0, end);
    }
    return r;
  }
  
  function base64Text(buf, i) {
    var n = (buf.length - i) % 3;
    if (n === 0) return buf.toString('base64', i);
    this.lastNeed = 3 - n;
    this.lastTotal = 3;
    if (n === 1) {
      this.lastChar[0] = buf[buf.length - 1];
    } else {
      this.lastChar[0] = buf[buf.length - 2];
      this.lastChar[1] = buf[buf.length - 1];
    }
    return buf.toString('base64', i, buf.length - n);
  }
  
  function base64End(buf) {
    var r = buf && buf.length ? this.write(buf) : '';
    if (this.lastNeed) return r + this.lastChar.toString('base64', 0, 3 - this.lastNeed);
    return r;
  }
  
  // Pass bytes on through for single-byte encodings (e.g. ascii, latin1, hex)
  function simpleWrite(buf) {
    return buf.toString(this.encoding);
  }
  
  function simpleEnd(buf) {
    return buf && buf.length ? this.write(buf) : '';
  }
  },{"safe-buffer":36}],42:[function(require,module,exports){
  (function (global){(function (){
  
  /**
   * Module exports.
   */
  
  module.exports = deprecate;
  
  /**
   * Mark that a method should not be used.
   * Returns a modified function which warns once by default.
   *
   * If `localStorage.noDeprecation = true` is set, then it is a no-op.
   *
   * If `localStorage.throwDeprecation = true` is set, then deprecated functions
   * will throw an Error when invoked.
   *
   * If `localStorage.traceDeprecation = true` is set, then deprecated functions
   * will invoke `console.trace()` instead of `console.error()`.
   *
   * @param {Function} fn - the function to deprecate
   * @param {String} msg - the string to print to the console when `fn` is invoked
   * @returns {Function} a new "deprecated" version of `fn`
   * @api public
   */
  
  function deprecate (fn, msg) {
    if (config('noDeprecation')) {
      return fn;
    }
  
    var warned = false;
    function deprecated() {
      if (!warned) {
        if (config('throwDeprecation')) {
          throw new Error(msg);
        } else if (config('traceDeprecation')) {
          console.trace(msg);
        } else {
          console.warn(msg);
        }
        warned = true;
      }
      return fn.apply(this, arguments);
    }
  
    return deprecated;
  }
  
  /**
   * Checks `localStorage` for boolean values for the given `name`.
   *
   * @param {String} name
   * @returns {Boolean}
   * @api private
   */
  
  function config (name) {
    // accessing global.localStorage can trigger a DOMException in sandboxed iframes
    try {
      if (!global.localStorage) return false;
    } catch (_) {
      return false;
    }
    var val = global.localStorage[name];
    if (null == val) return false;
    return String(val).toLowerCase() === 'true';
  }
  
  }).call(this)}).call(this,typeof global !== "undefined" ? global : typeof self !== "undefined" ? self : typeof window !== "undefined" ? window : {})
  
  },{}]},{},[1])
  //# sourceMappingURL=""